by Shalin Khosla
Greenhouse Vegetable Specialist
OMAFRA, Harrow, Ontario

The Canadian Greenhouse Vegetable industry has undergone many changes over the past decade. The redesign of the greenhouse structure, alternative growing systems, type of crop, cultivar grown, and the biological control agent used are some of the changes implemented. In all cases, the aim is to produce constant supply of high quality greenhouse product for the consumer.

The Canadian industry is delineated provincially. Each province has its own characteristic (climate, cultural and market) that has to be addressed. Ontario has the largest area devoted to greenhouse vegetables in Canada, followed by British Columbia and Quebec. Alberta has a small but strong industry. There are smaller areas devoted to greenhouse vegetable production in the other provinces. The size of operations within each province varies with largest ranges present in Ontario, British Columbia and Quebec. The size of each individual operation has increased over the past few years as operators are able to manage larger ranges as a result of the implementation of some of the aforementioned changes.

The majority of the production area in the greenhouses is devoted to tomatoes. Most of this acreage is devoted to beefsteak tomato production but there is a steadily expanding area devoted to TOV (Tomato on the Vine). The remaining portion of the acreage is devoted to cucumber and pepper production. The pepper area has increased steadily over the past 5 years with a dramatic increase in the area devoted to pepper production in Ontario over the past three years. Lettuce, herbs, oriental vegetables and medicinal plants continue to be developed at a slower rate in smaller greenhouses directed to sales to specific niche markets. The exception to this is the greenhouse lettuce industry where several large ranges in British Columbia and Quebec (4-7 acre ranges) market on a much larger scale as warranted by the size of the operations.

The production of greenhouse vegetables has shifted from operations growing in soil to those producing in hydroponic culture. The hydroponic culture in these terms includes bag culture (peat and saw dust), rockwool, foam, coconut fiber, lecadan and nutrient film technique (NFT). All large operations use these techniques with some smaller operations still producing in soil. Rockwool culture is the most popular production system used in Canada for all the vegetables. However, in British Columbia and Alberta, a greater percentage of the production is conducted using saw dust in bags or pots. This source is readily available in these provinces and performs well. In Quebec a portion of production occurred in peat, but is now declining and is being replaced with rockwool systems. Foam, as a growing media is becoming more popular, especially where a good irrigation system is available and recycling the leachate is practiced. Coconut fiber has been tried over the past few years with some major producers using the media exclusively especially in Ontario. One of the biggest benefits of saw dust and coconut fiber is that it is easily disposed of at the end of the season on farm lands, or used by the nursery industry as a supplement for pottings.

Nutrient film technique has increased in acreage (approximately 50 acres in Ontario) and is used to grow tomatoes and peppers.

The type of greenhouse structure used varies from province to province. Ontario has dramatically increased its acreage over the past 5 years with most of this increase in double poly constructed greenhouses. British Columbia on the other hand has used glass greenhouses as its most popular structure. Alberta and Quebec have used mainly glass constructed greenhouses, but now double poly constructed greenhouses are becoming popular. The trend to high gutter height has continued and most new construction has 16 ft. gutter height with a few of the newer operations building at 18 ft gutter heights. The greenhouse environment is computer controlled in all large greenhouse operations with some smaller operations still manually controlling the heating and venting systems.

Pest and disease management is conducted by the use of integrated pest management strategies. Biological control agents, cultural practices and greenhouse environment manipulation are some of the most common practices used to maintain a healthy crop. The majority of tomato crops use bumble bees to pollinate, while 60% of the pepper crops also use bumble bees for pollination. Cucumber crops do not require pollination as they are pathenocarpic.

Marketing strategy for Canadian greenhouse produce is conducted individually by each province. However, there is a greater cooperation among the provinces. Each province will target a specific market and provide point of sale demonstrations, on-site taste and recipe demonstrations. Ontario and British Columbia market a higher percent of their product in the United States. Advertising in the print media, as well as television and radio are means of promoting the greenhouse produce to the general public.

The general outlook of the greenhouse industry is positive as consumer awareness of high quality greenhouse produce increases.          (click on picture to enlarge)