Greenhouse history

July 27, 2020

Plants evolved in a variety of climates, latitudes, and geographies throughout the world, over time.  In places close to the poles north and south, hours of daylight would vary over the course of a year.  This would range from 24 hours of darkness in the cold of winter to 24 hours of daylight in the summer.  In areas closer to the mid belt the equator, there would be 12 hours of sun and 12 hours of darkness everyday, in all seasons.  Some places get 300-400” of rainfall a year, other places, less than 1”. 

People and cultures likewise evolved around the plants they could gather and cultivate, and the animals they hunted and domesticated.  Back in the olden times, before widespread world wide travel and commerce, you would eat what was available, when it got ripe or when it matured.  Or you would hunt the animals that migrated through with the rains or that congregated around the falling of jungle fruits.  Nature set the pace, and you the human followed it.  Sometimes the seasonal window for this fruit or vegetable was very small – asparagus and tomatoes in the summer, nuts like walnuts or acorns in the fall, and so on.  So people were always alert and on the move.  Also back in the day, in colder climates, before refrigeration, you had to preserve foods in some way so that you wouldn’t starve to death in the winter while you were holed up in your log cabin or mud dung straw house.  Some vegetables like cabbages you could keep in a root cellar underground or make into kraut.  Other foods you might have to dry, salt, and smoke to preserve them and keep them from becoming food for bacteria, fungus, rodents and insects.

The earliest plants folks figured out that if you took care of plants meticulously, you could sometimes extend their season and even plant them a little bit out of their regular comfort zone.  That is to say, if you blocked the wind, lavished attention on the plant babies, maintained the irrigation, warmed them at night with some thick masonry earth thermal mass, and so on, you might coax a fruit or two or more from a warm subtropical tree planted in a cool temperate place.  Or, you might get another two weeks of red red tomatoes on the vines, more grains and less pests on the rice crop.

During the times of naval superpowers and European conquests, plant worlds collided.  Plants from one area of the world were transplanted to other areas with the suitable climates and soils:  sugar cane from southeast Asia made its way to the Caribbean and Americas; tobacco and rubber trees of the Americas sailed back and rooted in Asia Europe and Africa.  Folks were shocked by the tasty tropical pineapple and mango, bewildered by the stinky durian.  People appreciated the easy and efficient carbohydrate production of the potato and the yam.  There was, and continues to be, a wealth of exchange as cuisines and cultures mixed, fused, adapted, and became something new. 

To meet this demand for fresh foods and foods available year round, the planting and growing of crops intensified and developed alongside horticultural knowledge and technological advances in materials and fuels.  Some plants are still best grown in the ground in a suitable place, in a plantation.  For example, chocolate trees grow best within around twenty degrees latitude north and south of the equator.  The same goes for black pepper.  The products are then shipped around the world for further processing or consumption.  Other plants – mostly annual or perennial herbaceous plants that do not reach a large size, plants with a quick generation time from seed to flower or fruit – became suitable candidates for growing  indoors in commercial greenhouses.  Edible plants, ornamental plants, medicinal plants.

People could now follow nature’s lead, but control aspects of light and air, temperature and humidity, water and irrigation, soil composition and fertility, and so on, in order to maximize the yield of plants, and produce flowers, fruits, seeds and foliage in all seasons.  That is to say, thanks to greenhouses, you could now harvest lettuce and kale in the middle of winter in Wyoming, cut a bundle of flowers in a hothouse in December in Canada, or be harvesting eggplants seven eight nine months out of a year rather than one or two months outdoors. 

When you go to the food market, you see the beautiful tomatoes on a vine, little yellow red orange sweet peppers, and cool perfect cucumbers.  By the checkout stand, amazing blooming orchids growing in bark for only $9.99.  At the florist, there are beautiful roses, a dozen for $15.  In the garden nursery, there are huge fat three four year old tulip bulbs and some fine anemone corms in the cardboard bins.  Or, you go to the cannabis apothecary, and smell that skunky big bud aroma in well packaged jars.  Well this is all a recent development in our relationship with plants.  If you appreciate this abundance and diversity, and understand a little bit of how this came to be, you will be acknowledging the wonder of greenhouses and the folks who work in them.