Starting Tomato Seeds Indoors

Start seeds indoors 6 to 8 weeks before two weeks after the last frost is due in your area. You want the 4 to 5 inch seedlings to be able to right into the soil after hardening off; and that is usually two to three weeks after last frost. 

Use a soilless potting mix in individual pots, or seed starting system. Sow seeds two to a pot, gently pushing them into the moistened medium about ¼ inch. Cover them lightly with the medium and water gently. Maintain uniform moisture and a soil temperature of about 70°F. Seeds should sprout in 3 to 7 days.

To prevent seedlings from becoming thin and spindly, set fluorescent lights about 1 or 2 inches above the developing foliage, adjusting them so that they are always about this distance above the top foliage of the growing plants for 6 to 8 weeks. Researchers have found that brushing seedlings gently several times a day reduces average plant height by about 20%, and promotes shorter, sturdier stems.

Transplant seedlings into increasingly larger pots once or twice before they go outdoors. Set them slightly deeper in the soil each time. Allow them to get large and sturdy before setting them outdoors. Ease their transition by exposing them to outside air during the day, then bringing them in at night, for a few days prior to planting out.

For more details see our file Starting Seeds For The Vegetable Garden