The Greenhouse Environment
When you step inside a greenhouse, you’ll feel like you’ve stepped into a perfect tropical oasis managed by science and technology.
Since the southern coast of British Columbia has a mild climate, our growers use recyclable Dutch Venlo style greenhouses.
This means our greenhouses are constructed out of single panes of glass, which allows for better light transmission into the greenhouse. The greenhouse is constructed of aluminum and steel and is designed to let in the most light possible. We do not pave over the floor of the greenhouse. Instead, our growers lay down a thin, white plastic cover that keeps out weeds. Each year that plastic cover is replaced when new planting begins.
Carbon dioxide is one of the major items plants need for photosynthesis and growth. It allows for stronger cell development, increased fruit set – the stage where the plant’s flowers are fertilized – and fruit production. Our growers deliver carbon dioxide through tubes made of thin plastic film that run at the plants’ bases. Growers adjust carbon dioxide levels so that it seeps out gently during the day giving the vegetable plants a bath in carbon dioxide.
Although the southern coast of B.C. has a mild climate, greenhouses still need heat on cooler summer days and during the other seasons, so plants can grow and thrive almost year round. Our growers use high efficiency boiler systems to heat their greenhouses and to maintain the region’s good air quality. Most of our greenhouses use natural gas, which is the cleanest burning hydrocarbon fuel. Carbon dioxide is a byproduct of burning natural gas and is captured and released into the crop.
Our plants are very sensitive to cool temperatures, so a “back-up” system, that uses a different fuel than the main system, is needed to protect them from killing temperatures. Some greenhouses use fuels other than natural gas as a primary heat source.
For example, some of our growers have moved to high efficiency, clean burning wood, or biomass, boilers because of high and fluctuating natural gas prices.
Many greenhouses store heat not used during the daytime in large water tanks. That hot water is used to heat the greenhouse during the cooler evening temperatures.
Our growers are committed to keeping British Columbia’s air quality excellent. We have a vision of responsible environmental stewardship and are proud to call the communities where we work and live home.
Watering and Feeding Systems
Our plants require the perfect amount of water and nutrients. We water and feed our plants through a drip irrigation system that puts water and nutrients right where the plants need it: at their roots.
We grow our plants in bags of porous sawdust or coconut fiber. That means nutrients and water stay in the bags and out of the ground water.
Our growers recycle their water and nutrients, pumping them back into the feeding system. Growers constantly monitor the watering and nutrient levels by computer. They adjust amounts fed to the plants based on the amount of light in the greenhouse. Many of our greenhouse growers collect rainwater and pump it into their watering systems.
The natural light level in the southern coast of B.C. is too low for vegetable plants to grow year round. This means we’re only able to supply our communities and others with fresh, B.C. grown vegetables 10 months of the year. Some of our growers are now testing artificial lights for year round vegetable production.
Screens that keep light inside the greenhouse are available. However, some of our vegetable crops are very sensitive to the heat that builds up if those screens completely enclose the greenhouse. Vegetable crops can die from being overheated.
This is a challenge for all greenhouse production areas. Researchers are working to develop screens that “breathe,” allowing heat to escape and the plants to thrive.