How Ontario’s greenhouse growers produce sustainable food year round

by | Apr 24, 2024 | Food and Recipes

Every year, Earth Day is a good time for a reminder of the need for greater sustainability in the way people live, work and eat.

Being able to adapt to the changing climate directly impacts the availability of food for Canadians and the global population, so for farmers who work closely with nature every day, sustainability is always top of mind.

That’s true in Ontario’s fruit and vegetable industry, where reducing energy, pesticide and fertilizer use or managing water more responsibly, has long been a part of doing business.

“Sustainability is part of our DNA as farmers, and we’re always looking for new ways to be more efficient, reduce what we use and produce more with less,” says Jan VanderHout, a Hamilton-area greenhouse grower.

Greenhouse production is one segment of Canada’s fruit and vegetable sector that helps make the country’s food supply more resilient – it enables the growth of fresh vegetables like cucumbers, tomatoes, peppers, lettuce and, increasingly, fruit like strawberries, indoors all year long.

In fact, industry statistics show that Ontario is home to the biggest greenhouse cluster in North America, producing more than 521 million kilograms of fresh produce every year.

Local, indoor production means a smaller carbon footprint from farm to consumer, and less risk of crops being damaged by temperature extremes, drought or flooding. That sustainability also extends to how produce is grown in greenhouses.

Re-using water
In many greenhouses, a fertilizer solution called nutrient feedwater is used. Any liquid the plants don’t need is re-circulated through the greenhouse and re-used. This limits the amount of water each greenhouse needs and keeps unused fertilizer from going into nearby soil and water sources.

Adding extra light
To grow vegetables year-round, greenhouse growers use additional lighting in the winter months to give natural sunshine a boost, so plants receive enough light to grow efficiently.

Capturing heat
A special boiler system helps growers capture and filter the carbon dioxide (CO2) from their heating systems instead of releasing it into the outside environment. They can then feed the CO2 directly back into the greenhouse as a natural fertilizer to help feed the plants.

As well, screens conserve the heat inside, reducing the energy needed to heat the greenhouse, while letting sunlight through to the crops and keeping cold air out.

Protecting crops naturally
Particularly exciting for VanderHout is using biological options instead of chemicals to control pests and diseases in the greenhouse, tools his family’s business first started using 30 years ago. That means managing certain insect pests, for example, with other insect species.

According to VanderHout, it’s important to note that sustainability for fruit and vegetable growers isn’t just about the environment. It’s also important that their businesses stay economically sustainable – and so buying locally-grown greenhouse produce on Earth Day, and all year long really does make a difference.

Find more information about sustainable food production in Ontario at

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