Did you ever wonder why certain varieties of seed are started indoors? It is usually because the days to mature harvest exceed the amount of time between your spring Frost-Free Date and your first fall frost. By starting these varieties indoors in advance, you will have a four to 14 week jump-start on the development of seedlings. Some varieties like to be started indoors so you can really pamper them with consistent moisture and warmer temperatures. Real warmth-lovers, like Eggplants, Peppers and Tomatoes, like to be coddled with 24-7 grow lights until they are 'toddler' seedlings when they will be able to handle cooler, dark nights.
Part One: Seeds to Start IndoorsIt's best to consider your seed order in two parts. The first should include the varieties that you must start indoors for transplant into the garden after your Frost-Free Date. You can find your reliable Frost-Free Date by using a nifty chart from the National Oceanic and Atmospheric Administration (NOAA). GO HERE and select your State from the pull down menu. This will generate a PDF file with a list of NOAA data collection sites in your State. In the left column, choose the location nearest or most similar to where you live. Then read across. Use the middle threshold number (32F) and right next to it in the Spring column, will be the 90% probability date. This is your all-important Frost-Free Date.
Eight-week General Seed-Starting Timetable Here is the general Seed-Starting Schedule for seeds that should be started eight weeks BEFORE your Frost-Free Date in your Horticultural Zone. Horticultural Zones 9 & 10: Start seeds indoors in early to mid January.Horticultural Zone 8: Start seeds indoors in early February.Horticultural Zone 7: Start seeds indoors in mid February. Horticultural Zone 6: Start seeds indoors in late February. Horticultural Zone 5: Start seeds indoors in early March. Horticultural Zones 1-4: Start seeds indoors in mid to late March.