Plant Pathology

Key terms and concepts in order of appearance

abiotic vs biotic disorders; vector carriers; the plant disease triangle;
monocultures; pathogens and infection; mycorrhizal, parasitic, saprophytic lifestyles; antibiotics; Integrated Pest Management; mechanical, chemical, biological and cultural control; disease resistant varieties; overhead water; plant pathogen specificity; bacterial pathogens; viruses; variegation.

Plant pathology

Plant pathology is primarily concerned with fungus, bacteria, and viruses. We will talk about their life style and life cycle in a bit. First some prehistory.

Plants like all creatures get sick and die. We have observed this since ancient times. Spots and blotches and the smell of rot. Wilted seedlings, distorted and twisted foliage. Scabbed and mildewed fruits. In the old times, before microscopes, we were not able to identify the microorganism that caused the disease. But, we could certainly see their symptoms and effects. And we learned that wet weather at harvest time, followed by some warm nights, was sure to end up spoiling the crops. On a large scale, a disease outbreak is called an epidemic. And if people were dependent on this one food crop, and the crop failed, famine was not far behind. Then its fighting, migration, and aberrant behaviors like cannibalism and genocide.

Plants have been fending off attack from pathogenic organisms for hundreds of thousands of years. This is why there are protective things like bark, pine pitch, oils in the lavender and rosemary, and latex canals in the stems. In other cases, plants would form beneficial alliances with certain fungi, which would allow them to fend off attack from other harmful and virulent fungi. Plants in a given population would be diverse in their genome, and hence harbor resistance against malevolent forces. So if one went down for this or that, the others might survive and pass on their beneficial traits. Nature’s workings – kinda like putting your eggs in a bunch of baskets to ensure survival, just in case.

Plants live within a comfort range that is based on their place of origin and evolution. Some like clay, others like sand. Some don’t mind sitting in water all day long, others want it always well drained. Some like it hot and tropical, others like it cool. These environmental factors we call abiotic. A – biotic = not of a living thing origin. These are things like temperature, humidity, water and light needs, and soil nutrients. If a plant is not living within its happy range, it gets stressed out. It can die, or become more susceptible to attack by creatures that ‘sense it is weak’. There are hordes of hungry creatures constantly on the prowl for food. It is like the motif of the snake eating its own tail. Nature is not all harmony and peace, it is a constant feeding frenzy.

An interesting relationship between plants and people grew out of the process of domestication and agriculture. In the wild, plants are tough, independent, loaded with spines and poisons and alkaloids, and relatively restricted to a certain area. But with humans cultivating them, they gave up a lot of their own defenses, and went cosmopolitan. They became softer, tastier, and unable to cope on their own. Rather than being individuals living in a jungle or a meadow or on a mountain top, they became a huge monoculture of clones living in rows with nothing else in between. And so this made them extra susceptible to ever present pathogens that were specific in their targets and always looking out for ‘easy game’ and ‘low hanging fruit’.

The pathogens are tiny and move easily. Anything that moves the pathogen from here to there is called a vector. Vectors can be abiotic – like the wind or water. Or they can be biotic – of a living thing – like animals or people. Pathogens can enter through the breathing pores of a plant, through the irrigation water and the roots, or through a cut, an opening, on the plant’s body. The most common biotic vector in town is a probably a gardener armed with a pair of pruners going from neighborhood to neighborhood. Or a gardener spreading pathogenic soil amendments. Or rodents chewing and tunneling and running hither and tither. Vectors that move disease worldwide are things like the ballast water of ships that is sucked in and pumped out of the sea at various ports; the wood pallet beneath the imported furniture with hitchhiking insects; and the spores carried in the muddy grooves of a pair of hiking boots.

Once the pathogen gets inside the plant, then it is infection and invasion. Take over, feed, move on. The disease wants to keep spreading and disseminating some more. It may form reproductive type structures that further its colonization, and disperse when the timing is favorable. The disease cycle can be stopped or wind down a bit if there is a freeze, a fire, or if the pathogen itself comes under attack by another pathogen. It does its thing, and fades into the background. The diseases are always around, but just do not exhibit themselves and take control unless the environment is suitable, and the hosts are weak and susceptible. This is known as the plant disease triangle of a successful infection.

In order to understand plant pathology we will describe a few local examples, and their solution or cures, if any. We will start with fungi. For some reason, as important as fungi are, people don’t pay much attention to them. Aside from the mycophiles who adore truffles and winter forays for chanterelles in the woods, most people are pretty much blind or ignorant of fungi. Or look upon them with great disgust and fear. They are a major and ancient group of organisms that date back probably a billion years. They, along with plants, make life possible on our planet.

Then you ask people – “Do you drink beer? Do you eat leavened bread? Bread that is puffy?” And they are like, “Sure!”. Well the yeast that makes that all happen is – a fun gi. And that alcohol? Thats its waste product. People like “What?! I’m drinking what?!”

Fungi are the primary cause of plant disease, in the ballpark at 80% of all plant diseases. On a more positive note, they also form a symbiotic relationship with plant roots and they help each other survive. These fungi are known as mycorrhizal fungi, and this mutualistic enterprise is said to occur in around 90-95% of all land plants. So it is not all bad, the scale tips towards working together.

Plus, along with soil bacteria, fungi are our primary source of life saving antibiotics. Think about that word – anti biotic. A substance that kills or is against living stuff. Chemical weaponry that fighting creatures use on one another, now re appropriated for use by us. Pretty cool stuff.

One fungus that eats trees around here is the oak root fungus. It infects trees through the roots. Its body of fine white strands of threads of cells takes over the vascular system of the tree and feeds and feeds. Eventually it clogs the tree all dead. So in the beginning it is like a thief – a parasite, it takes takes and takes while the host is alive. Then when the host dies, the fungus starts to eat its dead body too. It becomes a saprophyte, eating dead stuff to live. Two distinct life styles. Not all the fungi are this versatile, some are restricted to one or the other…

In the winter time, the oak root fungus sends up fruits to disseminate its seeds, so to speak. Except in fungi the fruit is called a mushroom, and the seeds are not seeds, they are spores. The easiest way to see spores is to take that portobello or white mushroom from the store and lay it gills side down on a piece of white paper overnight. Then you can see it drop all its spores. What color are the spores? (LAB)

The oak root fungus mushrooms are densely colonial and emerge in great numbers all together in the wet humid months. They drop their white spores that float out on the wind, hopefully to find another plant victim and continue the cycle.

So then if you are a gardener, a tree lover, what do you do? What are your options for dealing with such an “enemy”? Here are some of the scenarios:

If the soil dried up, the pathogen would not be able to spread so easily. If we did not irrigate the lawns and soils of Golden Gate Park, the pathogen would not be so abundant. But we are not turning back the clock and letting the sand dunes take over again. The water regime is here to stay, more or less. Nor is it feasible to remove all the soil and truck in brand new soil. Good luck, no go. So we are sorta stuck, abiotic factors wise.

If we removed the mushrooms every time they popped up, that might cut down the spread of the infection. A teeny wittle bit. But the actual organism is underground in the soil and in all the buried wood and roots. So even if you could get every mushroom before it opened to release its spores, taking away the mushroom does little to the actual organism.

Couldn’t we just kill them all and poison the fungus? No is the answer. It would be hard to treat and spray the soil to that extent. Unless you want to live in a hell of poison and gaseous death. People would be keeling over long before the fungus raised the white flag. Plus the fungus would likely come right back without repeated over and over again spray regime. Even then…

If we ate the oak root fungus, that could keep its population down. We would have to promote it as the most fashionable and cool thing to do. They are edible and pretty tasty. Plus there are a lot of them. As for whether they have accumulated heavy metals or other toxins present in the urban environment – not sure, pass. Probably best to be moderate or conservative if you plan on eating them regularly. Likely not the best of plans…

Okay to tally thus far. And inoculate you with this broad concept of dealing with pests called Integrated Pest Management. We do not control the abiotic factor known as the weather. We cannot stop the wind, eradicate the tides, or fight the climate. If you war against the earth’s forces you are sure to lose. We can adapt to changes, and help make the planet a livable happy place, but the mentality that somehow you are going to ‘win’ does not cut it. Life is life, not a game. It is not the appropriate metaphor for the pickle that we finds ourselves in.

In Integrated Pest Management, there are four basic methods for controlling pests. These are ways to keep pests at a tolerable threshold so that life can go on and we are not starving and dying, nor having cockroaches for overlords. When you remove the mushrooms by hand or with a tool, that is classified as mechanical control. When you spray stuff on em to kill them, that is chemical control. And when you or another animals eats the pest, that is biological control. With fungus, given its tenacity and power, our best general strategy is cultural control. These comprise preventive measures that minimize the growth and spread of these creatures.

There are many plants naturally resistant to oak root fungus. So ideally, we would only plant these plants. This is one method for how we manage many or most of our orchards of citrus and nuts, and our plantations of banana, potato, and so on. Plant the variety that is not going to get sick, the ones that are immune and are not so susceptible to the particular disease pathogen.

Another fungal disease that is common in our garden worth discussing is one called powdery mildew. It looks like well, a bunch of white powder on the surface of the leaves. Unlike the oak root fungus, this fungus does not make a mushroom. It does, however, make a little sac of spores for dispersal purposes.

In the garden, powdery mildew spores are floating around in the air, coming in with the summer fog, and if they should land on a tasty wet zucchini leaf on a nice warm day… They will germinate and grow, and then it is feeding time!

So lets run through our options. Protest the fog and activate the movement to ban low clouds full of moisture. Uh no. Invent a massive filter and fan to clean all the outdoor air of every single pathogen spore. Also no. Try to stick to things that are actually feasible and practical. Scrape every leaf clean by hand? No. How about a spray of some kind? Well you can kill the spores before they germinate, but once the fungus is in and feeding, it is hard to eliminate with the chemicals. Chemicals are best used as a preventive, not as a cure. Biological control wise, there are bugs that do like to eat powdery mildew, but it would be a stretch to have enough of them around to make a dent. So where are we? Back to the cultural preventive controls. If your leaves are not wet, then spores have less of a chance of germinating. If you keep the area clean of old dead leaves full of spores, less likelihood of infections. So keep overhead watering to a minimum, keep leaves dry, clean up the dead stuff full of spores, and plant your zucs with airy open spacing in a sunny spot. Thats about the best we can do.

Fungus is down. Next up is bacteria. Tag team duo.
One of the bacterial diseases that strikes plants around here is called fireblight. When a plant gets infected its branches look all burned and turn black. The vector or carrier can be insects flying from tree to tree, the rain splashing bacteria, or a gardener making open wounds with a dirty saw.

Many pathogens are specific in who they attack and feed on. This is called plant pathogen specificity. Fireblight is partial to members of the rose family. The rose family (Rosaceae is the proper name for the family) has many many members, not just the roses. Fruit and nut tree wise – almonds plums cherry peaches apples pears nectarines loquats quince medlar are all in this family. Berry wise – blackberry raspberry strawberry. Ornamental wise there is Spiraea Potentilla Geum firethorn and hawthorn. Weed wise there is Cotoneaster. The most common ones we see with infections around town are the street trees like ornamental pear or flowering plum. One day it looks healthy and happy. The next day a shoot or a branch is all inflamed and darkened. Sometimes a sore of a canker forms. And more die back down the line. Followed by more goopy ooze and more bacteria…

Bacteria are funny creatures of an ancient lineage. They are everywhere. Again, they get a bad rap with the antibacterial soaps and anti bacteria wipes and solutions that kill 99.9% of all bacteria. Truth is most of them are helpful and beneficial and we would be dead without them. Whether as members of our own intestinal fauna, or as members in the soil responsible for recycling and nutrient cycles and exchanges, bacteria have important jobs and deserve our recognition and respect.

That said, I did not like the staphylococcus bacteria that gave me swollen bloated limbs and brought me to the brink of sepsis then amputation twice. Nor do I enjoy seeing my bag of potatoes in the cabinet succumb to bacterial soft rot and ooze all over the place with that stinky nasty smell. Still, I do not intend to go to war against all bacteria. That would for sure be a losing battle.

In the yard, if fireblight is present on a rosaceous plant, we cut off the infected limbs and try to contain the infection. If you cover the wound with a clay slip, that may be helpful. Maybe. And we disinfect our tools in between uses with lysol spray, or a little propane torch, or alcohol. That is about all we do. Bacteria like warm and humid conditions, and feed and multiply once they somehow get a foothold into their prey and host.

In humans, when we have bacterial infections, we use antibiotics like penicillium or amoxycillin or clindamycin, depending on the type of bacteria and the location of the infection. The source of all of our antibiotics are fungi and soil bacteria. These medicines are liquid substances that fungus and bacteria use to repel one another in their competition for food – bits of decayed leaves or the skin of a gopher. In the recent past, before the invention of antibiotics, peoples would use natural substances of a similar effect to treat wounds. These included things like honey, plant oils and resins, clays.

There are some rare instances where we will inject tree trunks with antibiotics also. But this is usually not done because it is expensive and does not always work. So we live with our companion and occasional foe with awareness and caution. Bacteria.

Last one – viruses. Then we all go home to rest
okay ‘higher’ fungi grows as little threads from a spore
finds a compatible mate amongst four distinct sexes
forms a massive pulsating underground network called mycelium
and congeals together into a shroom to spread more spores

bacteria divides itself over and over again
and it become stronger, more diverse, and more resistant
by exchanging bits of genetic material with each other
so no sex, just a little hand-off time to time
they come in all shapes and sizes
and move around together beating their little tails


Size: super little

Lifestyle: get in, get em to make more of me, everybody out.

Structure: a secret instruction code surrounded by a protein armor that functions as a spy, camouflage, and attack organ.

Effect on the plant: If the plant is working on making virus bits rather taking care of its basic duties, then the machinery is gonna get gunked up and malfunction. Viral infection results in leaf splotting mosaic patterns that are not green in color, rings of dead tissues on the stems, stunted plants that look like a permanent wax museum bonsai, and leaves curling and twisted with tiny gouged holes like it had been hit with tiny size #20 shot if there was such a thing.

Vectors and manner of dispersal: insects with a mouth and a gut full of the virus, feeding and spreading, feeding and spreading. A gardener grafting a scion piece to a rootstock piece, inadvertently serving as an in between. A farmer touching and cutting plants while walking through the crops. A tiny round worm in the soil sucking here, then sucking there. Virus hiding out in the seeds, and going where the seeds go.

Specificity: Not sure. For the most part as far as we sorta know, plant viruses stick with plants, and do not infect animals and humans. More work needs to be done to elucidate results…

Application: biotech companies using plant viruses as messengers and bosses to inject into plants and have them perform specific functions. Purposely encouraging plant viruses that create cool looks like ‘red tulip flower streaked with white’, “lime orange New Zealand flax foliage”, “spotted snake plant” and “polka dot yellow griselinia”. Sometimes this is called variegation.

Herbaceous perennials

This is a good time of the year
to work on the herbaceous perennials
summer is coming to an end
food has been made and stored
flowers are spent

What is an herbaceous perennial?
well for one it is herbaceous
herbaceous in botany horticulture speak
means the plant stays bendy and squishy,
soft tissues that do not harden and become stiff and rigid
herbaceous, not woody
shrubs and trees – they are woody, not herbaceous
most grasses and rushes – herbaceous
bulbs and corms – herbaceous
blue bells, columbines, delphiniums, coneflowers and poppies
all herbaceous

Herbaceous is different from an herb, like a kitchen herb
herbaceous is different from herb, like street corner slang for cannabis
herbaceous is not a particular plant, it is a description for a plant tissue type and structure

Perennial means it lives for more than a a couple of years
could be five
could be one hundred
so relatively long lived

Some herbaceous perennials
come from a place with cold winters
so they are accustomed to tucking themselves back into the earth
underground, for a spell
hanging low during the cold period when the sun is low in the sky
and there is ice and snow cover

Other herbaceous perennials
come from a place with hot hot summers
in order to survive
they die back, go dormant, and take a rest from photosynthesis
when the sun is hitting hard, and there is hardly any water
be still and quiet

There are also herbaceous perennials
that are evergreen in foliage
they are green and persistent year round
happy in our mild coastal climate
getting by just fine with the occasional winter rains

As maintenance gardeners and plant lovers
working on the herbaceous perennials
you may –
(1) deadhead old flowers
(2) remove the brown and spent foliage
(3) rejuvenate the plant by cutting it all back to the ground
(4) collect seed and store it in an envelope to grow later
let’s go to the field and give it a go

Deadheading is removing the faded spent browning flowers
with the hope that by removing them, the plant will send up more flowers
for us to enjoy
this works because the plant wants to make seeds and reproduce
by taking away the faded flowers with the just-beginning-to-form fruits
you have frustrated the plant in its reproductive endeavor
so it will try again, provided there is sufficient water light and warmth
to keep going

Here is Digiplexis in action
you can see some cut flower stalks of past deadheading
you can also see that the plant sent up more flowers to achieve its end goals

This one is Agapanthus
watch the flowers drop off one by one
observe the fruits start to swell up with seeds
seeds that start off white, then turn black with age
okay here’s plenty of work
deadhead em anytime!

Now when you see a shasta daisy, or a coreopsis
or a california buckwheat, or an osteospermum
you know what to do
to keep the flowers comin’

When you remove the brown and spent foliage
it just looks cleaner and taken care of
like a gardener has been through there
this patch of Chasmanthe is all finished for the year, the corms have retired
these little colonies have been shrouded for most of the summer
would be good to take a pair of pruners to em
or snip them with a pair of really sharp shears at the right angle

This swathe of grasses is also all done, dropped its seed, just a fiber skeleton left
but these grasses dont actually belong in this lecture
cause they are not perennials, they are annuals – mostly oats Avena

Like with this daylily
you just reach in and pull out all that brown dead stuff
and the plant perks up a bit

Like with this clump of Scilla bulbs
see the gardener’s touch?

Only thing is, sometimes you gotta wait it out
ideally, if nobody is complaining, you wait until the plants’ leaves go all brown by themselves before you dive in with pruners
that way the plant pulls all the green goodness back down into its underground parts
and stores it for next year
if you cut them prematurely, that is – interrupting its natural cycle
it is kinda like dropping a couple of hundred dollar bills on the ground as you walk away from the bank, having just made a withdraw
if you are able to, follow nature’s rhythm, don’t force it

That said, in nature, even the dead brown leaves serve a purpose

they act like a blanket of insulation

shielding and protecting the parts below

during hard times

As it dries up, down into the ground go the irises:

When the plant is all done
then you go in
for example, this Alstroemeria, see the difference a few minutes of gardening makes?

Sometimes though, you came a little too late, and the plant already started its next growth cycle
like this other patch of Alstroemeria around the corner –

you can still work on it, just try not to yank and cut all the fresh growth

These Amaryllis belladonna are still blooming:

This Amaryllis has that look that says
“That’s it, I’m all done. Lemme rest”
unless you want to save the seed, this is when you can go in and cut it all down

So that next August September it will look like this again

Maybe you are a maintenance gardener
who is secretly harboring wishes
to be a nursery person or a master propagator
well then you want to keep an eye out on the fruits
and start to collect seeds
while you are in the garden

Collecting seeds is almost the total opposite of deadheading
if you want to have germinating plant babies
you have to leave the maturing fruits
the fruits will tell you when they are ready to be harvested
usually when they turn brown
you will have to put up with people saying things like
“Why you leave that? Its so ugly?”
or “Cut it down already, theres no more flowers, are you lazy or what?”
usually, I just shrug, smile, and wait, and wait some more

Wait until I can get a handful of the fairy’s fishing wand Dierama seeds:

Until I can fill an envelope with nutka reed grass Calamagrostis seed

Until my pouch is chock full of four o’clocks MIrabilis

Until Canna edulis’ perfect spherical seeds literally drop from the open capsules

This then completes the life cycle of the plant
and your training as a gardener
if you understand how all this works

Once in a while its challenging to resist
the urge to cut the plant all the way down to the ground
especially when –
the plant’s leaves are full of mildew
its leaves are tattered and bug eaten
rust is pervasive
and frankly, the plant is making you look like a terrible gardener
but then you open a seed pod or two
and discover the reward for all that hard work and patience and tolerance
well there it is! Red runner beans in purple and black

Hold up! I know that it’s not looking so good, but please don’t cut it down yet! what are those things at the axils of the leopard lily?! look like teeny baby bulbs with roots?! do you think I might be able to grow them?!!!!?

A tidbit about potting mixes:

The stuff we are growing the poinsettias in is called Pro Mix. This is from the back of the package. Check out other brands of potting mixes – many have similar ingredients.

Canadian sphagnum peat moss comes to us from bogs, coniferous forests, and wet tundras of the north. Over eons it can build up thick in such places as mosses grow, live, then die. It is able to absorb a lot of water; hence in the olden times it was commonly used for diapers or for wound dressing. It is also useful as tinder, or to burn for fuel. These days it is mined to be used as potting mix. It is acidic in pH, in the 3.0 -4.5 range.

Perlite is the little white exploded expanded volcanic rock used to aid in drainage and aeration and keep the soil mix permeable. This ensures that the plant roots are happy and not sitting in wet goopiness.

Dolomitic and calcitric limestone are added to balance the acidic peat. Limestone is pH 7.5 -8.0 and basic. Most plants like a pH of about 5.5 – 6.0 – 7.0.

Some plants prefer an acidic soil: rhododendrons and ericas (pH 4.5 – 5.5), or the oblong leaf sundews (pH 3.7 – 5.3). There are also other plants that like it more basic and alkaline like the Pinguicula butterworts (pH 7.0-8.0). It is important to keep the pH of your soil within a certain range, otherwise nutrients can become unavailable to plant roots. You can test your soil’s pH with a slurry method, using a pH meter or paper test strips.

Wetting agents are chemicals added to help the water to infiltrate and evenly wet the soil mix. It does this by breaking apart the ‘stickiness’ of water (lowering its surface tension). A common wetting agent when we use when watering street trees is Dawn dish soap. If you do not use a wetting agent, you may see the water just sort of roll off the soil. This is because water is cohesive and prefers being bound to itself rather than breaking apart and going into the pores and cracks of the soil.

Mycorrhizae is fungus root. The species in this package is “Glomus intradices 1 active propagule/gram”, which is about 27,216 spores per 60 pound bag of potting mix. So this is a relatively new additive to potting mixes. What scientists found out is that in nature, plants are working with partners underground – fungi. Plants give the fungi some of the sugars they make from photosynthesis, and in return fungi bring the plants water and nutrients they collect from all around. A mutually beneficial symbiotic relationship. There are fungus that live on and around the plant roots, as well as fungi that live inside the roots. Glomus lives inside and in between the root cells.

The whole idea is that by inoculating the potting soil with these fungus spores, the spores will grow into a network of fungal threads around the roots. it will then help the plant improve its nutrient and water holding ability, and increase the intake of of nutrients like phosphorous. By the way, Glomus intradices was recently renamed to Rhizophagus irregularis. On the package, it says “do not sterilize or pasteurize”, likely because that would probably kill the fungal spores.

If you want to learn the different names and kinds of hard materials we use in the landscape, best to go to the rock yard or the lumber yard. They showcase all the gravels pebbles decking flagstones bricks boulders and blocks and such you could ever dream of.

If you want to see how things hold up over time, go walk around the neighborhoods and parks and see the hardscape in action. How they weather, how they perform with use. If you want to see how things are built, then you will have to sneak a peek during the construction phase. Here’s a few pictures to get started. With the caveat that the whole world is your classroom if you keep your eyes open and have your observation skills honed razor sharp.

What happens to a concrete paver driveway if the base was not prepped properly or water and erosion and subsidence a problem?

What happens to a retaining wall over time if the weight of soil and water is too great and there is no way the wall can release that pressure? (The wall is not permeable in any way)

What are two ways to make a raised bed planter? Which one is permeable?

What about a new modular type system for building a retaining wall that is faster and easier than hauling huge blocks of heavy material or making a massive wooden form?

Dry stacked is the retaining wall made with no mortar. So it is permeable and allows built up pressure to be released.

How do you make a curved concrete structure?

What happens to four foot tall fence posts or trail posts in a windy and sandy area?

What lies underground where tree roots go?

Who invades my beautifully done stepping stones and walkways?

How do you give strength to a concrete structure like a slab or a wall? What kind of a skeleton must it have?

Can you tell the difference between pressure treated lumber and regular lumber?

What kind of edging is used here? How many different kinds of hardscape do you see?

And here? What kind of edging? What might be a potential problem with small round pebbles as a hardscape surface? Do you see the two areas (mulch and pebbles) as staying discrete over time?

Is the decking attached to the house? Is there appropriate flashing? Will it hold the weight of a thousand pound pizza oven imported from Italy? And all the people gathered there to partake of the bounty?

Is the flagstone on a stable base? Will the surface drain well when the first rains hit? Is it thick enough to be durable and not snap? Does it sit flat and even so that theres no tripping hazard, especially after a few glasses of wine and some fresh baked pizza? Are the joints between the flagstone filled with sand or grout? Is the flagstone mortared to a concrete slab? Permeability and drainage!

What grows on the wood walkway that sits under the shade, with overhead irrigation and rainfall?

How do you like the always green, never needs mowing turf?

For some reason student was having difficulty

seeing the parts of a flower

mainly the female and male parts

this is part of the challenge of online instruction

whereby something relatively simple

becomes complicated

whereby a lab exercise that is fun and shared

becomes an exercise in isolation, clicking and wondering


flowers are still blooming everywhere

so do a walkabout, make some new friends

I went around and took pictures of flowers to show you

was going to label them all, but that would take all the fun and challenge away now wouldn’t it?!

take a good look, keep an eye out for the male stamens

and the female pistil with the ovary at the base

males can be few to numerous, with a bit of fuzz look to them cause of the pollen, you are looking for a long oval with a slit more or less

females are in the center

the tip is sometimes a little club, or divided into a fork, or a cross, or partitioned further

also note that the timing is sometimes staggered

that is to say, the males may be ripe and mature, while the female is hardly developed

in another flower, the males may have already faded and dried, along with the petals, while the females are just starting

we will start with a few pictures labelled

then the rest is up to you. good luck finding the sex parts on flowers:

The following flowers

I skipped em

cause the parts are easy to see in person with a razor blade and a hand lens

not so easy for me to show you online

The rose family is tricky

cause theres sometimes a whole lotta pistils all cluttered together

plus the way the breeders hybridize em

the parts can be a mess to discern

heres a couple of rose family flowers:

Once in a while you run into one of these around town

a princess flower

We will end this entry

with a puff of plant sperm pollen


Addendum to Greenhouse Coverings
September 5, 2020

Ultraviolet light basics

About a billion years ago ancient plant ancestors called algae formed or came to this planet and started to multiply. Their energy making activities created oxygen gas as part of the photosynthetic process. This gas became part of the protective layer called the atmosphere that blocked out most of the life destroying ultraviolet rays hitting the earth. It also allowed the proliferation of lifeforms that depended on oxygen to breathe and survive. The dominance of plants continues to this day. Plants and algae create, maintain, and protect the conditions to make life viable on our planet.

Most of us cannot see the light waves that are not in the visible spectrum. What we can see with our eyes is a tiny portion of what is happening. We see red orange yellow green blue and violet. Plus the mixtures of colors like pink magenta and turquoise. Scientists investigating the properties of light found that there was something happening at the extreme ends of the rainbow of light. Above the purple violet was something else – they called this ultra violet. Ultra meaning more than/extremely/excessive, like Ultra man! Beyond the red part of the rainbow they found another kind of wave – they called this infrared. Infra meaning below.

As the scientists made more observations, they discovered a wider range of waves in this electromagnetic spectrum that is the energy reaching the earth from the sun. They identified waves of energy with super short wavelengths like gamma rays and x rays. Waves that were so short and tiny and full of energy that they could easily penetrate bodies of living organisms. Scientists found waves of energy with long wavelengths, like microwaves and radio waves.

Over time, we have harnessed and made use of the physical properties of these waves: x rays at the doctors to see past the muscles but see the dense bones; microwaves in the kitchen to excite the water molecules and heat up your supper; microwaves for radar to detect motion and measure movement and velocity; radio waves for radios, mobile phones, wireless networks; infrared waves for night vision scopes and heat seeking missiles.

Of the ultraviolet rays of light hitting the earth from the sun, much of it is absorbed by the atmosphere composed of nitrogen and oxygen gas. This is good, because otherwise most of life on land would be dead. The UV waves that do make it through can break chemical bonds and damage cells in humans. This is why we ask you gardeners to wear sun protection. Long sleeved shirts and a nice wide brimmed sun hat, not a baseball cap. Otherwise the tips of the ears and back of the neck are uncovered and often susceptible to skin cancer melanomas. Folks with darker skin can produce more natural sunblock which is melanin, they do not burn so easily. Fairer folks ought to wear sun block and reapply accordingly. Otherwise the sunblock wears off with time, and the sun’s UV rays start baking the skin cell/sunblock residue matrix. But UV light is not all bad. Vitamin D is made when your skin is exposed to the sunlight and that little bit of UV; Vitamin D helps you absorb calcium, magnesium, and phosphate. It also helps your immune system and protects you against disease. So some sun is good for you.

In the garden we also harness UV light for its beneficial qualities. In a pond system we will use a UV light alongside the filter to kill the algal spores in the water. This keeps the pond water nice and clear and not green. UV light is also used to disinfect and treat water at the wastewater treatment plant before discharging it or before it is channeled to the recycled water stream. In entomology class we collected scorpions at night by shining a hand held black light while wandering around the desert. Scorpions fluoresce and glow in response to the UV light, and are easy to catch this way.

So back to coverings. Glass has the excellent light transmission. It absorbs and blocks all of the shorter wavelength UV rays (UV-B) but lets in most of the longer wavelength UV rays (UV-A). The plants in the glass greenhouse get all the light they need to proceed with photosynthesis. Glass, composed of sand, limestone, and sodium carbonate, is great stuff!

In a poly film covering, however, the plastic covering is composed of long chains of carbon and hydrogen; it degrades and breaks down in the presence of ultraviolet light. Before long the plastic is discolored, cracking and falling apart. Therefore, a chemical compound that absorbs the UV radiation is added to the plastic in the process of manufacture to prolong its life. These are similar compounds as found in sunblock and cosmetics. This way, your plastic greenhouse holds up over time, and you can grow happy plants.

Yes it looks nice and neat. The enclosure probably keeps some of the animals from urinating or defecating close to the tree also. And, you may be able to sit on the edge and eat your lunch there on a sunny day. But, how would you like it if your most important interface – where the base of your trunk meets the earth and soil – is damp and wet all the time? Covered and piled up with rock and gravel and dust and dead leaves and weeds. Trapped and held in with nowhere to go.

Sometimes trees fall down and hurt people and property. Occasionally they fall down and miss everything all around ‘em. Often, the cause is natural – they are old and sick, they are growing unbalanced in the loose sand, el nino storms are strong and water has saturated the soil. Other times, human care and maintenance may play a role in the outcome. Hard to say. What is important is that while you are working and playing around these massive huge creatures, you pay attention and watch out. Lest a broken branch fall and hurt you. Do you see the hanging limb caught in the crotch here? Imagine it comes loose and tumbles down. If you are a gardener – best to caution tape and cone off the area until the arborists can come and take care of the problem.

You plant a big tree in a small space. It ain’t ever gonna fit right. It ain’t ever gonna stop growing till it dies. It ain’t ever gonna mature at 15’, more like 80’ then start growing sideways. As the tree grows, roots swell, and the sidewalk cracks. Gotta fix it. So you bring in the jackhammers and forms and bags of concrete. The reciprocating saw cuts the roots in the ground real good, and the saw blades are cheap. You cut the roots off clean and level. Some of the roots you cut are the fine fibrous roots in the upper surface. Down lower, you cut some of the larger thicker anchoring roots five six inches thick to almost a foot wide. Then you pour the concrete over the top. Once the new concrete is screeded and dry, nobody hardly even takes a second look.
But like Gus says, “the damage has been done”. It might take five years, ten years, twenty years before the tree succumbs, fails, and falls. By then people are blaming the weather or the canker disease or something else. More likely if you were a real detective you could trace it to the big root cuts, or the big pruning topping cuts, performed years before. That is where the disease got in. That is when the rot started. So design and plant with size and proportion in mind. The ol gardener refrain goes –
“Right plant right place”.

The tree planters. They do it with the best of intentions. But the follow up is so so. They think “We are saving the earth and planting trees. We are going to protect you (the tree). You are going to grow up straight and tall. We are going to make sure of that by binding you nice and tight!” But they forget to come back and loosen the straps or the bars or the cage or the grate. They forget that as a tree grows, it gets bigger. They do not recognize that a tree needs to move, needs the wind to blow it back and forth, for its roots to grow strong and firm into the ground. So then one day, five years down the line, somebody finally removes the stakes and the ties that were too tight to begin with. And the first wind storm, the tree falls over because its roots never rooted on its own, never went looking for water on its own. It was dependent on external supports placed there by an undependable human. Oh well, better luck next time!

Girdling is when the tree gets sick and dies from strangulation. The conduction of water and nutrients gets stopped up and jammed. This can be from plastic rope that got tied around its trunk. This can be from a root in a container that went around and around until it choked itself. This can be from a piece of wire that would not let go. If you care for your trees, this does not happen. Loosen the ties. Prune the circling roots.

If you view a tree as a thing, as an object, not as a living creature, then you will treat it as such. You may see the trunk as a fire hydrant, and be unaware that dogs are burning the tree with their nitrogenous waste stream, burning it until the bark peels off. You may use the tree basin like a trash can or an oversized ash tray which it resembles. You may plant a tree too close to the house because you thought it was like a sculpture that would always stay the same size. You may fill a tree cavity full of concrete because you figured the problem was one of hardware – like the tile and the grout, the shower tub and the caulk, or the drywall and the spackle for the nail hole Most of these things, most of these treatments, the tree just accepts and tolerates, and keeps on growing!

The bud union is where the tree was budded. That is to say the bottom part (the rootstock) is one plant, chosen for its disease resistance, its ability to dwarf the size of the tree, or other qualities. The upper part is another individual plant (a bud), chosen for its pretty flowers or tasty fruits. The two were stuck or taped together back in the day, and now they grow together as one. Where they meet is often a bump of a swollen scar. The union. You can commonly observe this on flowering cherry trees, roses, and fruit trees.
A weak V shaped crotch is a tight narrow angle between the two trunks. It occurs commonly on the sweet gum tree Liquidambar. Sweet gums have the maple looking leaves and a fruit that resembles a small mace ball with spikes all over it. It has a fruit that will pop your bicycle tire’s inner tube. When your crotch is narrow like that, the growing bark becomes rolled inwards with the years, eventually resulting in a a weak crotch that is prone to splitting. When you put a two hundred pound arborist climbing in the tree pushing hard at that junction then kaboom – half of it breaks off and down goes the arborist. So be careful around them especially if they are rotten.

These days it is not fashionable to leave a stub. This is based more on aesthetics and cosmetics rather than health. Some people will say that if you leave that ‘dead wood’ stub it will attract fungal pests and infect the rest of the tree. Not really. The tree will usually compartmentalize that chunk, slowly suck out its nutrients, and let it die. Most any organism that lands and eats it will be a saprophytic dead material eater, not a live tissue eater. In the country farmers like to leave a little stub to hang a hat or a jacket or a tool, so that stuff don’t get lost in the bushes. But in town, it is best to leave no stubs for looks and for the standards…

Double leaders are tricky. If it is an older tree, and the crotch angle is U shaped and strong, then just leave it. Trees do not have to have only one strong leader, they can have two. But if it still a young tree, and the leaders are thin and not yet really developed, and you want to nip one of them, then go ahead.

Spurs. Once, a beginning gardener was asked to prune an apple tree in the springtime. He thought it was no big deal even though he had never done it before. He did not even ask for advice or look it up in a book or use the internet. He just went for it. He finished pruning and it looked real good. Most of the year went by. Then the client called to ask why there was no apples at all this year. Gardener felt a little bad, shrugged, and went to look up what spur wood looked like…

Here is a Magnolia tree that has been topped. What do you think? Does it look okay? Why would you top a tree? Did you know it is technically illegal to prune in this manner? And that you can be fined hundreds of dollars?

The three cut method is still a good and valid way to prune larger limbs off a tree. Only change in recent years is this: On the second cut, prune it right to the undercut, not a little aways like in the illustration. Straight shot to the cut, not letting it snap where the cuts are separated.

Couple of changes here. New standards recommend no fertilizer for the first year or so. Let the tree get used to the site first. And the backfill – use all the same local native soil you dug and excavated, not a 50/50 mix of native soil and organic matter. The logic and theory is that the tree will adapt and do best in the stuff it has to live in, not some compost leafy barky organic matter that is going to decompose and let the root ball subsides and sink deeper. This way the trunk base – soil interface does not get covered with dirt and soil and moisture and rot. Better to plant the tree a tiny bit high rather than low.

As we progress in our knowledge of trees as living organisms, we have made changes in how we treat them near our dwellings. We are emphasizing tree health over simply tree cosmetics. We are broadening our view of what an ornamental tree is, and what is ideal in a given landscape. We are seeing trees not only from an engineering model’s stand point, but also seeing a tree as a tree.

Have you ever seen a wild old plum, one planted by itself on the edge of a field? Have you seen how it is a dense thick tangle of trunks and branches crossing meshing and exhibiting a sort of mad exuberance? Well that is its natural wild form. Even the domesticated town plums would like to look like that a little bit, but most of the time us peoples don’t let them. “Stay in your little square!” So when we prune them hard in an effort to ‘correct their poor structure’, they fight back with a ton of new sprouts, thin woody upright sprouts on the branches, sprouts we call watersprouts.
The tree is filling out all the pruned-away empty space with energy producing leaves. It is filling in gaps in its canopy where light is being wasted. What we call “wrong’, ‘ugly’, ‘incorrect’ and ‘bad’, the tree knows as ‘good’. Good for survival, good for making food for itself.
Ornamentally speaking, sometimes a light natural prune is more beneficial over time than a heavy hard prune that will set you down a path where every year you are fighting to make the tree do what you want it to do. This instead of letting the tree do what it has done for the last hundred million years just fine, and just helping it along as a gardener to make it look its best.


Sometime I get people asking me
why y’all still draw by hand?
its so tedious, and slow
and if you make a mistake you gotta start all over again
why don’t you change up
get with the times
go digital
use computers
they are so much more
efficient, uniform, and perfect
compared to the human mind and hand

This is true
and we offer two courses at our community college
in landscape design
in the advanced class we get into some software
and click away at the screen
importing 3 d plants from a virtual warehouse
visualize a space while orbiting and zooming in and out
snapping lines of exact 8’ – 2 1/2” straight retaining walls with ease
these are good advancements, improvements
we evolve with the times, and the new clients’ expectations and wishes
I do not dispute this, nor its importance

On the other hand
we have many students who are
ex accountants ex chemists ex doctors ex IT specialists
ex software engineers ex architects ex ex ex
who have spent many many too many hours at the keyboard
and don’t really want that anymore, at least not all the time
they want a balance
they want to be with fluid nature not rigid culture
they want to know the world that functions as a web of connections
take a break from the boxy world of top down hierarchy
so they turn to plants, hoping for some new connections and friends
some sweet scents and down time
the last thing they want to do
is to sit back in that ergonomic chair, hooked up
or we have many students fresh out of high school
who have already spent countless months, perhaps years,
with shows and video games and movies and social media
probably more time with a screen than sleeping
probably more time with a screen than with people
so to get them to learn the basics of drafting, and the origin of the art and science of horticulture
we start at the beginning
we start with simple hands on objects and basic observation skills of the outside world
allow that process to take hold
and grow like a vine

there is a warmth and person feel
that comes from a hand drawn picture
in the big architecture firms that can afford it
the renderings, the perspectives, look at how they beam
they are hand drawn, not machine drawn
a good artist can bust out a drawing
and exceed the speed of a computer’s drawing
a computer plan may have to be
photographed uploaded edited imaged cropped moved and saved
whereas the hand drawn plan is relatively simple to execute
paper, pen, straight edges and ruler

In addition
in those human drawn lines
there is emotion and manna and mana
embedded in the picture are a persons experiences and trials
maybe a person working through their traumas and fears
they are all there
its kinda meditative really, a drawing
a process with a defined start and finish
a relatively straight one, not one full of zig zag mazes and infinite scroll down loops

drawing by hand, there is less of an inclination or ability to
edit and change, save and redo, paste and track, copy and rename
it is more of ‘bang’ shot beginning to end
less of a strain on the mind doing the this or that, analysis, more this or that
nor is there as much the anxiety of a plan that seeks to be perfect
every little detail, perfect
yes a person did this, it might even have a tiny tiny mistake or two
the gist is that
we are drawing a plan, a preliminary idea, something to get us off the ground
something to ground us and root us, into the earth
thats all
we are not drawing the blueprints for a high tech science instrument to the milli milli accuracy
we are not designating the specifications for an advanced prototypic 3 billion dollar machine
we are just
making a garden

computer designs are good at the straight lines
not so good with the
the gentle curves or serrated edges or dynamic flows
that is part of garden design
thats the softness, the gentleness, the peacefulness
we seek in nature
maybe one day there will be cookie cutter factory designed gardens
custom clicked gardens
gardens you can just swoosh through the email and plop down
instant garden
one size fits all garden
rubber molded garden
eternal never changing garden
plastic never dying garden
really, is that what you really want?
ponder this a little bit longer, what you are getting into…
a garden is a personal thing, ya know…
it is a treaty a compact an agreement a covenant
between a sanctuary and people
it is installed by a contractor
maintained by a gardener
and designed by you
a visionary who can weave all the disparate elements together
and sink it down deep deep deep

So back to the hand drawn plans
you get to touch tools and learn their special function
tools that are not icons, tools you can touch
you get to make mistakes and crumple up the paper all mad
no you shouldn’t break the computer that cost 1000 dollars, throw it out the window
no matter how frustrated it makes you…
you get to see a vision in your mind travel through your nerves and muscles and become reality
you get to be actively engaged, whole body married to the creative process
the whole thing is so cool and fun
tactile, textured, full of vibrant colors
this is why we still
draw by hand
at least initially… in the first semester of class
yes I know, I am with you
I am not a luddite resister going around town in a horse pulled buggy
using a hand cranked flour mill and sitting around a wood fire
yes, the year is 2020…

There is something else. In art and design classes they use this one book called Drawing on the right side of the brain. It challenges you to see things in different perspectives, as a way to balance the right and left spheres of your brain and become a better artist.

Well for those of you who did not grow up learning this stuff – the left side of your brain controls the right side of your body, and the right side of your brain controls the left side. Funky right? Also, the left brain is more associated with the analytical logical ‘rational’ side of behavior. What we think of more as ‘the head’. So science and math and languages. Theres the left brained engineer, investment banker. Leaders in big industries and tech, business. Whereas the right brain is more associated with creativity, intuition, visualization, spatial abilities – more ’the body or the gut or the heart’. So art and music, sports, poetry and stories. Not as much valued in our society today, materially speaking anyways. Besides sports. We are primarily a left brain dominated culture. A right handed culture.

Imagine the left brain sees the world as geometric shaped boxes, black lines on white paper. Squares and more squares. The right brain is full of beautiful colors, but not well structured. Splatters and stuff everywhere. Put the two of them together, and you have the world and life and a garden. That is the design. On many occasions scientists have visualized the solution to a problem by seeing images in their dreams. These are the scientists that have the left and right brain interface well bridged and working together.

Having come across this in high school, I am not sure of the research and source at this point, but simply retelling it as a point of interest. Back in the day they were investigating the brain and treating the mentally ill with whatever they could think of. One of the methods they came up with was cutting off sections of the brain, this was called a lobotomy. They hoped that in so doing they would be able to restore function and health in some way shape or form. In the course of these experiments, they did an interesting study of the right and left brains, stimulating parts of the brain and seeing what happened. When they stimulated the left side the patient articulated language normally, when the equivalent right side was stimulated they would cuss, ‘like a sailor’. That is to say, these cuss words in our vocabulary, normally avoided by most of us civilized folk in day to day life, come from another part of the brain. They are emotion charged and you might say primal, having to do with scatological or sexual phenomenon that is common to all animals. So these words serve a function beyond mere insults. Out of the right brain emerges a punctuation mark in the midst of chaos, expressing equalizing and decompressing the mind and the situation. Basically the right brain is a little bit repressed and neglected in our culture, and so in designing and drawing a plan, we hope to give it some light and find that balance. This is not to say that you should go around the house screaming profanities at the top of your lungs cause you are stimulating your right brain this way. Its just to recognize this tilted scale and bring it back up to level.

Site inventory:

So we looked at this site, and squared it off like a rectangle for the inventory, to make the first time easy and encouraging.  Just this part, not the L of the plant bed goin around the corner.  You can do the same at any spot.  Start to observe the plants and the basic elemental forces that surround them.



What do you see?

Plant wise, we see three princess flower bushes in the front, and about seven trees of Pittosporum tenuifolium kohukohu tawhiwhi as a hedge behind it.  A tree in the back corner coming from the neighbor is catalina ironwood, and underneath the ironwood some irisy looking things – chasmanthe.  On the ground are chips.

Water wise there are two irrigation boxes, one open with a purple headed quick coupler showing.  And another box not sure what is inside.  No visible signs of sprinklers or drip system, at least initially.

Hardscape wise there is a sitting wall retaining wall there on the right. Say about two feet tall or so.  And the blue metal fence behind it.  Lets look at it from another angle:



We took a compass reading.  If you were one of the princess flowers with your back to the pittosporum hedge, you would be facing east.  So it is pretty protected from the onshore wind with the hedge and the hill and houses back behind it.  It is not out in the open like full on southern exposure but not too shady either.  Protected.  Not a bad spot that is why these purple flowers are blooming and blooming and blooming.  Alright, goin in for a close look.  Heres one box.  Purple color indicates the water inside is recycled water.  Meaning that it was flushed out one time to the water and waste treatment plant, they cleaned and disinfected it, and now its back watering the landscape.  Not drinking water, recycled water for landscaping:


This the other:


And hope its okay to take a look.  ????.  Pass.



Go on up to the back, aha! Found a pop up sprinkler.  Not sure when it comes on…



Beneath the ironwood is a large metal cage.  It is part of the water system, a backflow prevention device.  We will illustrate the principle and practice at a future time.  For now keep an eye on it, once you have seen one, you will see them everywhere.  Parks, schools, museums, etc.



It would be nice to dig around in the soil and see what you are dealing with.  The day we went it was foggy.  The soil at the surface looked all wet.  But as soon as you dug down less than half an inch it was dry as a bone.  What does that mean?  When is a bone dry?  In the desert yes but usually it is moist and getting gnawed on by rodents for its calcium content.

Anyhow, when I went back later in the day to take pictures, even the surface had dried.  Like this – a thin layer of mulch, a little bit of sandy soil.  Should have had gloves on.  Sorry.  Safety first!



If you stand a little ways back you can then see the how the hardscape and the garden slope and irrigation run off would drain into a grate and catch basin.  The man hole cover there leads to the sewer:



So a rough drawing not to scale would look something like this:


Thats all for site inventory.  We will do them over and over again until you are intimate with the world and for all intensive purposes become a flowering plant.  Or a fern if that is your preference.

Now we are going to get a little bit more accurate and less rough.  When you set out to measure the yard, it is helpful bring some graph paper.  Overlay the space  with a grid with an x and y axis.  Bring your graph paper. Easiest to have two long tapes and stretch em out if possible.  Nice to work with a buddy system.  This way you will be able to measure existing plants and structures with ease.  We will use this brick raised bed as an example.  I see a metal post on the left, aeonium succulents all around, an echium that was pruned hard that did not or has not come back yet (the bare thing of all branches), a santolina the gray silver foliage plant on the right, and some wooden fencing.


So let’s stretch out the tapes.




Length is here.  Thirty feet!:



Width is here. Six feet ahhhh six inches.   Round up.  Close enough!




And lastly the height. Let’s say 10″ tall:



Now you can put this on your graph paper.  And write copious notes all around to try to remember this site.  Do note that I am drawing with a  thick sized sharpy marker for online communication and emphasis.  Don’t do like this in the real world!  Use a nice pencil or pen, not a marker.



Lets say we want to draw the existing metal pole in our plan.  You would look on the x axis of where it lines up.  Looks about 1′-4″ here.


Then along the y axis.  Looks like it lines up at about 4′ -2″.  What is the diameter of the pole?  Two inches?  Got it.  There you go…IMG_4237


So for every site, when you are doing your site survey and taking your measurements, just overlay, impose, layer a grid on top of it.  This will improve your accuracy and make sure things are drawn to scale.  Pick a nice origin (0,0) and go from there.  Start at a square corner, take it X and Y.  Even awkward diagonals and circles and curves are easier this way.




Now on to drafting.  And eventually transferring that drawing on graph paper and that rough sketch into a presentable form.

These are the basic tools you ought to have.  The white thing is an architects ruler, not an engineers ruler.  Make certain of that.  The little numbers on the ends should say things like “1/4, 1/8, 1/2, 3/16”, not “10, 20″ and so on.  Standard measurements not metric.  There’s two plastic triangles here:  one is a 45 45 90 degree triangle, the other is a 30 60 90 degree triangle.  I prefer the orange one for our class.  We will use it for an isometric drawing later in the semester.  The black ink pen is a specialized technical drawing pen for drafting purposes.  They run about 1.50 or 2 or 3 bucks, each.  They are good in that their ink dries right away so it doesn’t end up smearing your paper, and they usually dont bust out on you and leak link out the tip like some ball point pens do.  .5 or .8 mm are nice sizes for the pens.  Underneath is a drawing table.  The table should be able to fit paper that is 18″ x 24”.   Ideally you have a quiet studio space to work, maybe even a drafting table that tips up real cool like so you don’t get as bad neck strain.  But if you do not you will have to make do with a dining room table and its surface and edges.  Perhaps pad it with the piece of cardboard that comes with the pad of drawing paper.



Scale.  The whole idea of scale is that you cannot draw a garden life size on a huge piece of paper.  Sure that would be cool as a modern art project but it is not practical to show a clients such a thing. So we will shrink it down so that it fits on our piece of paper.  It must be accurate, to scale, so that a contractor can look at it and be able to figure out how big the deck you designed is, or how much concrete has to be brought in, and where to place so and so plant.  So get your ruler out and look at it.  Flip the triangular toblerone shaped ruler until until you find the one side that says 1/4 on one side and 1/8 on the other.  The 1/4″ scale goes from the right and proceeds left.  It is the lower row of numbers here that say 0 2 4 6 8 and so on.  Ignore the 46.  So if you want to draw something that is 8 feet long, start at the 0 and draw the line to the 8.  The bunch of fine lines to the right of the 0 are to indicate the inches within one foot at 1/4 inch scale.  It is a common mistake to start at the very right.  Do not make that mistake!  Start at the zero 0!!!IMG_4196



Heres the ruler on the left side with the 1/8 inch scale. This scale runs left to right.  Use the numbers on the top row this time.  Where it says 0, 4, 8, 12, 16, 20, and so on.  So an 1/8 scale is half the size of an 1/4 inch scale.  These are the two scales I am asking you to draw and practice for this lab.  You can fudge a little bit in the drawing when it comes to itty bitty inches.  Say if something is 14′-2″ you just go between the 14′ and the 15′.  Half way between the two is 14′-6″.  From 14′ to 14′-6″ you go about a third of the way and that is 14′-2″.  Engineers are like what!?  You landscape designers are so inaccurate!  It should be down to nearest .0001 mm!!  But this is a garden we are talking about.  If you are off by 2 or even 3 inches it is usually not that big a deal.  You can always make adjustment in the field by pushing a bit of dirt that way, adding half and inch, half and inch there and making up the difference.  On the drawing itself, the pencil or pen line is already as thick as an inch or two even in the garden.  So do not sweat it.  The minutiae.  Move on.IMG_4197


Here is an illustration of some of the scales on that same architect ruler you have.  It is depicting what 40′ looks like at various scales:



Okay lets draw.  We will start off with how you are not supposed to draw.  If you just tape your piece of paper on your drawing board all willy nilly then it will look like this.  Your lines will not be square with the paper.  Everything will be tilted as if it wants to slip off the side of the hill.



Then as you continue to draw the headhouse, you may be tempted to draw in all of the dimensions.  To be thorough, to show that you are doing a lot of work.  And the labels too!  It may look like this after a while of intensive work.



You are thinking I am going to go over the top and get extra credit.  What about if I put some plants in there too and hardscape and make the whole thing into a garden?!



You have now gone way too far over the top and it is time to start over.  Lets start at the beginning again.  Again?!  Crumple up the mistake and throw it to the compost and worms.  They love cellulose.  Fit your new sheet of paper to the drawing board by feeling along the edges so they all line up tight and square.  Tape em down.


Edge like this:



If you know the dimensions of the plan you are going to draw, a helpful hint is to cut out a piece of paper of the same size, and put it on the paper.  This way you can space it out so that is is centered and looks just right.  This is a good method if you have two or even three separate drawings all fitting on the same piece of 18″ x 24″ paper.  Layout.



Then you start to draw.  Make two dots, connect em.  Connect em in one smooth stroke one smooth breath.  No thinking just go.  By the way I am drawing with a fat sharpy permanent marker so that it shows up well on the screen.  On your drawing you should be using pencil.  Later we will go over it with an ink pen.  For now pencil.





You will be using the ruler as you go, to get the correct measurements on paper.  Sometimes I will run it along the top this way so that it is straight.  Make sure your T square is set firm against the edge of the board no wobbly actions, or else lines will turn out crooked.  Then its eraser marks and frustration and maybe ripped paper start over again.  So draw light pencil lines that are visible but do not put too much weight behind it.



You can also use the triangle like this if you do not want to have to move the T square from side to side then up down then side to side.  I did smudge the marker there.  You can avoid smudging by using the technical ink drawing pens, and also some people tape pennies underneath the T square so it is slight teeny bit elevated and smudges less.  So the ink does not get trapped underneath the hard flat edge.



So just take the dimensions I’ve given you and draw the figure.  I’ve simplified it here a bit but it is the same idea.  Draw the dimensions lines indicating the length and width.   Just those two are fine for our purposes.  Too many dimension lines will take away from the overall CLARITY and CONCISENESS of the drawing.  If a contractor wants to know how big the patio you have drawn is, they can pull out a ruler and measure it.  The drawing is to SCALE.


These extension lines indicate the extent of the dimension lines, the end points.  The termination point is indicated with arrowheads or a dash.  Choose your own style, just be consistent throughout your drawings and dont switch it up back and forth.  CONSISTENCY.


Finish the labelling and you are done.  Easy clear simple and concise.  That is what we are striving for.


Here is a student’s sample from last years.  Thank you Josephine!  Okay give it a shot.  Notice how the 1/4 inch scale is bigger than the 1/8 inch scale.  Those are doors swinging open.  If you were here I could show you the door to the back classroom, the door to the shop and garage, and the double doors that lead to our greenhouses.  Alas…


C’est tout!  Fini!  Hopefully not too bad for a first draft.




With regards to safety. Safety starts with awareness and your mind in sharp focus. A pair of kevlar chaps and carbon fiber hard hat and a thousand barricades will not help you if you are not present. You have to acknowledge that nature and the world we live in is dangerous, and can cause harm to you. This can happen if you are not careful, but can also happen because it is some crazy fluke. So you want to be prepared irregardless, and try to avoid getting hurt.

Hazards in gardening are many. The soil is full of bacteria. Some of it is helpful, others can get inside of you and try to take over and eat you alive. You will swell up with an infection, the bacteria will make their way into your blood, sepsis amputation and death are not far off. Lucky these days hospitals are equipped with antibiotics made from fungus and precisely other soil bacteria. Otherwise lights out. Many people who reminisce about the old times, or who have an idyllic vision of nature, often get into trouble because they want to put their bare hands in the soil and be one with mother earth. Maybe out in the country but in town it is right dirty and best to wear gloves. If you have an open wound for sure avoid contact with the soil. If you get an open wound or cut from a hori hori knife or a long barb of blackberry remember to wash it out good with soap and water. Not sloppy either wash it good.

Another common hazard is stinging insects. Around here the worst is yellow jackets that nest in the ground cause sometimes you don’t see em till its too late, you’ve already stepped on their nest and they come roaring out really mad. It really sucks when they go up your pant leg or chaps, are trapped, and really panic and sting and sting. Then you have to drop your drawers in the middle of the park and hope your underwear is not too unsightly. It would be a good idea to know if you are allergic to the venom. You can get tested by a doctor or wait and see if you have never been stung before. If you are allergic and persist in the great outdoors get an epi pen which is a shot of epinephrine which is adrenalin, so that you can inject yourself in the leg and not go into shock. Then get help. Just so you know bumblebees can sting also, as can of course honeybees. These are all insects in the colonial matriarchal clan called the hymenoptera. Ants are in this group too. Lucky here we do not have the stinging red ants in the south nor the massive conga paraponera bullet ants of the tropics. So before you go into a patch of ivy to weed it, observe to see if some yellow and black bugs are flying here and there. Watch where they are going. Preventive practices is a big part of being safe. Black widows are a concern too. So watch out for irrigation boxes and cleaning out the potting shed that hasnt been touched for a decade. Mostly with the spiders it is like with the moray eels, don’t just stick your hand down in some place some hole you cannot even see. Give em some warning, stir around with a stick. You are not superman or the widow whisperer.

Something along the lines of stinging things but human created is hypodermic needles. Around here there used to be a clean needle exchange. You bring in a dirty one, you get a clean one. Then it went to you bring in a dirty one, and they give you four clean ones. Now folks working on the street tell me its unlimited clean ones. So the needles, after being used to inject plant based chemicals, end up in the litter, in the ground. And if you are gardening, sweeping raking leaves and branches, that needle will likely end up jabbing you right in the hand as you go to pick it all up. So what do you do? Use a scoop shovel, use a rake, avoid contact. Bring a sharps container for such days. Until public health starts to care about you, you gotta care about yourself and take precautions.

Branches and trees are a big safety uh oh. Any tree worker can tell you stories. And stories. And stories. Its not that trees get mad and want to kill us, its just that they are so big and sometimes rotten and unpredictable. Yes physics and leverage and the lean are all important to know, but some trees… Eucalyptus in particular… Then when you are dragging branches or cutting a hairy trichome covered limb, you realize that wearing some eye protection does not make you a nerdy weenie, its just being safe. Like my buddy Gus says, “You only get one pair of eyeballs”. Haven’t heard of eyeball transplants or artificial AI eyes or stem cell grown eyes yet. Protect them. And hearing protection goes along with that too. Of course both Gus and I are probably a little guilty of this, and so do as we say, not as we do. So many good friends be jackhammering, shooting their 12 gauge, running that chainsaw, going to a rock concert, with no hearing protection at all. It takes a while but sooner or later. You are trying to talk to them. “Hey! Hey! Hey there you over there!” But nothing, they cant hear you no more! They see you motioning, and they smile back, but they are in a cloud. Sigh.

There is endless hazards working in the landscape and garden (rodent poo, human feces, poison oak, holes in uneven terrain, etc) and I won’t bore you with much more about safety. Just pay attention and dont rush things. I’ll finish this section with a story about an accident that occurred a couple of years back.

We went out to do our labs after lecture. The lab was pruning. One student went to prune the Lophostemon Brisbane box tree out front of our compound. He had a long 12’ fiberglass pole pruner and saw combo, and was pruning this tree from below. “I know what I am doing, I do this all the time”. Gus is supervising from a distance, sitting in his little electric cart. Then as the student pruned a small branch, it was falling down, he wanted to catch it. So he let go of the pole and the pole saw came down right on top of Gus’ head, hitting him square, luckily with the blunt part of the metal end not the sharp part, otherwise he would have died right then and there. Now Gus is one tough codger, born 1934, been through polio at 19, and been through all sorts of garden arborist diving fishing hunting accidents. So he took it like it was nuthin, still smiling and conversing with the students. Blood gushing and staining his white hair all red. I think some students were about to faint; we had some super competent nurses Nancy Lewis and Ana Trejo and Arete Nicholas as students in the class, and they luckily helped him out good. Scott took him to the hospital. If Gus was a wee bit younger he probably would’ve just shook it off and wrapped it with some duct tape and stayed to finish the job! So lessons were learned by everybody. No use blamin’. Gus learned to position himself a little further from the action, and wear a hard hat. The student learned not to let go of the pole saw. And I learned that I should tighten up the supervision and keep hammering on about the importance of safety.



The reader we use is thirty or forty years old. So some of the information seems dated. I appreciate it for the elements of gardening that haven’t changed in all these years, and for its history. I will give an up to dated overview of our use of pesticides here, so that the information in the reader will remain useful and relevant to you as a student of horticulture.

In order for you as a gardener to spray any pesticide compound with an EPA number, you have to have a certified pest applicator’s license. Or at least a certificate. You can get this by passing a test and paying the appropriate fees. This is administered by the Department of Pesticide Regulation. Funny ironic thing in reverse is that any homeowner can spray darn near any substance they can get their hands on, without a license. So if they choose, they can spray that 50 year old bottle of lead arsenic nicotine sulfate methylmercury all over the place. Nothing stopping them. But you, as a professional, has to follow the rules. So if they hand you a bottle of skull and crossbones labelled pesticide and be like “Hey put this on those weeds in the sidewalk cracks”, and you are not licensed. You say, “Sorry I am not licensed, but you are welcome to spray it yourself”. Or, better, you can have them bring it down to Recology Sunset Scavenger to their toxics recycling yard.

We will introduce to you, over the course of the class, other methods of prevention and control of pests. Often, the pest is just the symptom of the problem. The problem is usually attributed to the overall culture and care of the plant. Attributed to basic things like water and soil and climate. But if you choose to use pesticides, these are the basics. Pages refer to the reader.

Read and follow instructions. (Pages 196, 197, 204 – 208)

Identify the pest you are trying to kill. No use using a snail bait if the pest is an aphid. Chemical poisons are specific! No one pesticide kills em all! (Page 198,199)

Decide the proper formulation to use. If you use a bait, make sure you confine the bait somehow and do not inadvertently poison the client’s prized pomeranian or poodle or pug. Sprayed aerosols can drift in the wind and kill unintended targets. Powders may be rained out and not stick to plant material and lose their effectiveness. (Page 200, 202, 233)

An ideal insecticide would kill your unwanted bugs, then break down rapidly into harmless ingredients. Unfortunately an insecticide that breaks down rapidly would also require more frequent applications, which are expensive in both labor and materials. Some of the more effective insecticides are longer lasting. Unfortunately this means that they may be passed on to more than your target species and can destroy the beneficial insects as well, such as honey bees and even marine invertebrates as the chemicals flow down the rivers into the seas. Sometimes an insecticide is also a piscicide, a fish poison. So again, you would have to know this and be careful if you are spraying a rose bush for aphids with rotenone, next to a fish pond with 10,000 dollar koi swimming about.

If you are using herbicides timing can be key. The poison must be translocated down to the roots for an effective kill. If the plant is going dormant anyways, or is stubborn and able to close off channels of movement, then all your spraying will be for nothing and the plant will sprout back happy as can be from down below. (Page 201)

In general, there are fewer gardeners who apply pesticides in town these days compared to times past. There is still a market for arborists who spray for insects because trees are a high profile high value plant that is not so easy to switch in and switch out. But otherwise insects are either tolerated or the whole plant is trashed and composted if it is buggy. One of the most effective methods to apply herbicides is by using a wick or a brush. This way you are only using a small and controlled amount of herbicide, and there is no drift like from a sprayer. It is useful for killing a tree dead after you cut it down, and do not want it to resprout and resprout for years and years to come. And you cannot afford, or there is no access, to bring in a stump grinder. (Page 209 – 212).

The Eugenia plant was commonly planted as a hedge and ornamental plant some thirty plus years ago. Then a bug showed up and gnarled the leaves and made the plant undesirable. Gus used to spray for the Eugenia psyllid with acephate trade name is Orthene. He would always remark about its strong smell, like sulfur. In recent years people have mostly yanked the plant because spraying is temporary and the bug comes back after a while anyways. The fruits however are tasty (if not sprayed with Orthene) and can be harvested for a nice jam in spite of the appearance of the leaves due to the psyllids feeding. By the way the plant was known as Eugenia but is now known more properly as Syzigium (Page 214-215)

The most troublesome mammalian pest we have in the landscape are gophers and rodents.
The most effective way to kill gophers is using traps. Many gardeners then leave the dead gophers out for the hawks to come by and eat them just like in scenes from the asian steppe eagle hunters or Conan the Barbarian. Another way we protect plants from gophers is by planting them in a gopher basket. It works well initially, but over time as the plant roots grow larger, they often struggle and are constricted or girdled by the thin metal cage they are living in. (page 217)

wire cage

Rodents are one of those do if you do, do if you don’t pests. They must be controlled; otherwise, living in such close proximity to us, an overpopulation of rats can cause many terrible health problems. Current solution is usually with poison bait boxes, located conveniently throughout the city and checked on by various Integrated Pest Management personnel. Rat poisons kill them through internal hemorrhaging. Once in a while a hawk or an owl that feeds on the rats also becomes sick. We find the birds in the parks hopping about, stumbling, and sickly. They usually end up dying in the bushes somewhere where ravens crows ants or rats then feed on their carcass, and so on and so forth. (Page 217)


Specific insecticides (Pages 203, 218 – 220)
With regards to insecticides you have a choice of biological, oil, soap, botanical, and synthetic insecticides (and some others mixes or unspecified). Biologicals are bacteria that eat bugs. Oils kill by suffocation and restricting the breathing of bugs. Soaps break down their layers of protection around their outer exoskeleton, botanicals are chemical compounds derived from plants, and synthetics are human created compounds mostly derived from petroleum sources that became popular after World War II. The four main classes of insecticides are organochlorines, organophosphates, carbamates, and pyrethroids. More on this in the future.

Specific insect and invertebrate pests (Pages 221- 230)
As far as chemical type controls – our common insect pests are aphids (spray with water or soap, pyrethrins), caterpillars of moths and butterflies (Spray with the biological known as Baccillus thuringiensis B.t. or the botanical called rotenone), earwigs (sprinkle diatomaceous earth in their path), slugs and snails ( Sluggo iron phosphate or beer to drown them in), mealy bugs (oils or soaps), root mealy bug in containers (ethyl alcohol), mites (neem oil).

Neat to read how nicotine sulfate was such a common insecticide back in the day. Nicotine is one of the most toxic alkaloidal substances known. You can make your own poison spray by soaking cigarettes in water.

Weeds in general (234, 235, 239, 240)
If you spray weeds, they will die but you will still have to go back and remove their brown bodies or pull them up and out of the cracks. Some weeds are extremely resistant and do not die even from repeated applications of weed killer. As new products pop up you will have to try them at different times of the year, with different plants, with different treatments, to see if they work.

Specific weeds (236, 238)
Many weeds are edible or medicinal or cover crops that build the soil. As people have become less hunter gatherer foragers and more ‘civilized’ and landscapes more ‘controlled’ we have come to view these plants as undesirables and invaders and bad plants. Amongst these are chick weed, (tasty edible), dandelion (coffee substitute, greens, flower wine), pig weed (edible), and plantain (seeds are laxative, close relative of which is Metamucil).

Specific herbicides (203, 241, 242)
Many herbicides lost their effectiveness over the years as weeds became resistant to them. Also, many herbicides have been banned as people learned that their effects would travel along a chain and a web and affect all of life. For example the fumigant methyl bromide was a common herbicide used in the strawberry fields. If you are just eating a box or two of strawberries it might not seem a big deal. But imagine that you are the worker who is breathing this stuff in and out over the seasons. It is has been banned for the most part since 2005. Others pesticides been banned in Europe and Australia and still used here, or vice versa. With weed killers, there are selective (kill only some kind of weeds) and nonselective (kills all the weeds, or so it says on the advertising and packaging). There are pre emergent sprays (that is a layer of poison that sits on top of the soil preventing weed seed germination) and post emergent sprays (for weeds that are already up and at it). There are lastly contact herbicides (kills the part of the plant it touches), or systemic ones (poison can be moved, translocated, to the leaves or roots after it is sprayed.) Whelp, this is all for now!