Some growers here raise tomatoes under cover, but most varieties need a longer season than offered in Calgary. Tomatoes 'on the vine' from British Columbia are sold here, and we use those, or sometimes get the varieties grown under shelter.
We like BLT but with added cheddar- calorie count be damned ! Tonight we are having burgers made with lean Canadian beef, tomatoes, cheddar, sliced onion, and spiced with oregano and Hy's seasoning salt and finely chopped onion.

Calgary, east of the Rockies and on the edge of the foothills, gets the chinook cloud condition- Winds from the west are lifted by the mountains, and a cloud forms over Calgary. Look to the west and the mountains are in sun, look to the east, and see the edge of the cloud some 20 miles east.
Moreover, at 3500 feet altitude, the growing season is short. Go 200 miles north to Edmonton, a thousand feet lower, and more plants reach maturity, tomatoes (still not all) do better. We had a little farm near Edmonton and we could grow strawberries in the field.