As a warm weather plant, tomatoes can be a challenge to grow in colder climates with short growing seasons. Growing tomatoes specifically developed in or adapted to Canada or other cold places--such as Siberia-- will insure a successful crop despite these difficulties, and not all those varieties are difficult to find. Many familiar tomatoes of garden centers are adapted to cold weather.
Perhaps one of the most familiar type of tomato--available everywhere--is Rutgers. This heirloom variety developed in 1928 by the Campbell's Soup Company is an old standby for good reason. It is an all-purpose tomato--good fresh or canned--and contributes high yields of flavorful medium-size fruits on strong vines. It is a determinant tomato, which means it grows to a fixed size and ripens within a short span of time.
Lesser known, but something of a groundbreaker when it was introduced in 1952, Fireball was one of the first determinant tomato varieties on the market. It is a bush type, producing loads of 2-inch red, crack-free fruits early in the season.
The name says it all. Cold Set is an extremely hardy determinant variety that can be direct sown in the garden at temperatures of 50 degrees Fahrenheit, and produces seedlings able to withstand temperatures down to 18 degrees F. Developed in Ontario in 1963 specifically to set fruits under cold conditions, it also ironically withstands extreme heat, growing well from Texas to Alberta. It produces 2-inch red fruits with good flavor, but is not disease resistant.
A Siberian indeterminate variety, Momomakh's Hat is named for the crown-style hats worn by Russian Tsars. It is compact and early for an indeterminate, producing quantities of medium-large heart-shaped pink fruits on 4 to 6 foot vines. These tomatoes are very sweet and full of flavor.
Another of the Siberian tomatoes, this is a green-fruited beefsteak variety named for its color. In Russian, Malakhitovaya Shkatulka means "malachite box". (Natives of the region make pretty, green boxes from that green mineral in the Ural Mountains.) The medium-large olive green tomatoes are reputed to be very tasty, and they make flavorful green ketchup. This is an indeterminate variety developed at Svetlana Farm in Russia.
A plum-shaped, determinate variety hybridized in 1975 by the Horticultural Research Institute, Ontario, Veeroma is a cold and wet tolerant substitute for the famous Roma paste tomato. Fruits are medium in size and red.
Sub-Arctic tomatoes are a series of early, cold tolerant varieties developed in 1976 by the Beaverlodge Research Station (Alberta, Canada), of which Sub-Arctic Plenty is the most widely available and productive variant. Like all the Sub-Arctics (including a cherry tomato variety) it produces clusters of small tomatoes (ranging from barely over 1 inch to 2 inch) hidden in the centers of the compact plants. They ripen very early and all at once, making them convenient for canning. The Plenty tomato, though most prolific, is not the tasty of the group. Sub-Arctic Maxi usually claims that honor.
Other Cold Tolerant Selections
Stokes Alaska, Siberian, Quebec 1121, Scotia, Benewah and Ida Gold are other good choices for Canada.