Seed starting

The most common failure point

Leggy, pale seedlings are almost always caused by insufficient light. Seedlings need 14 to 16 hours of direct light per day. A south-facing window is rarely enough in late winter and early spring.

Most gardeners use supplemental grow lights positioned 2 to 4 inches above the seedlings, raised as the plants grow. A shop light with daylight-spectrum bulbs works; expensive grow lights are not required for seedling starting.

Count backward from transplant date

Start seeds indoors 6 to 8 weeks before the last expected frost date for most vegetables. Starting too early produces leggy, root-bound seedlings that transplant poorly. Your local extension office publishes frost dates by county.

The transition to outdoors

Seedlings grown indoors must be gradually exposed to outdoor conditions over 7 to 10 days before transplanting. Start with a few hours of filtered sunlight, increase daily. This process (hardening off) prevents transplant shock from sun, wind, and temperature changes.