Siberia 
50 days,
determinate — This tomato variety sets fruit very early. They are bright red and weigh up to five ounce. Reported as being capable of setting fruits at 38ºF, however, 'Siberia', like any other tomato, is not actually frost hardy.
'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.