Start indoors mid-March to early April with bottom heat. Then grow seedlings on for 6-8 weeks at around 10°C (50°F). Early season tomatoes can be planted out when night time temperatures are reliably above 7°C (45°F). Other types should be transplanted out when night time lows are 10°C (50°F) or warmer. Days to maturity are from transplant date. Optimal soil temperature for germination: 25-35°C (68-95°F). With bottom heat seeds should germinate in 7-14 days.