Step 1: Timing
Start indoors in early spring over bottom heat. When seedlings germinate, remove from the heat and grow under bright lights. Grow seedlings on for 6-8 weeks at around 10°C (50°F). Early season tomatoes can be planted out once night time temperatures are reliably above 7°C (45°F) - or later. Other types should be transplanted out when night time lows are 10°C (50°F) or warmer - or later. Optimal soil temperature for germination: 25-35°C (68-95°F). With bottom heat seeds should germinate in 7-14 days.