Siberia 
50 days,
determinate — The productive 'Siberia' tomato plants produce very early in the season due to its ability to set fruit in cool temperatures where other varieties will not. Reportedly, it is capable of setting fruit down to 38ºF, however, 'Siberia', like any other tomato, is not actually frost hardy. They are bright red, globe shaped, and weigh up to five ounces each.
'Siberia' was discovered by Ron Driskill, a horticulture teacher at the Jack James Secondary School in Calgary, Alberta, Canada, on sale at a local nursery. The nurseryman told him that a woman touring Canada from the Soviet Union in 1975 stopped by the greenhouse and supplied ten seeds. The unidentified woman told them that the variety was being trialed in Siberia at that time.
Mr. Driskill saw its potential and became a big promoter of the variety to Northern gardeners, first giving seeds away in exchange for a self-addressed stamped envelope and ultimately starting a small, family operated seed company appropriately named "The Siberia Seed Company." Each packet contains approximately 20 seeds.