Grow Lights for Seedlings
Technique
Seedlings need strong, steady light to grow compact and sturdy indoors. In most homes, window light alone is not enough for reliable seedling growth.
How to do it
Hang or place grow lights directly above the seedlings and keep them close enough to provide strong light without overheating the plants. Turn the lights on daily for a consistent period and raise them as seedlings grow taller. Rotate trays if some areas receive less light so plants stay even. Check moisture often because strong light and warm indoor air can dry containers faster.
Timing
Use grow lights as soon as seedlings emerge and continue until plants are ready to harden off. They are especially important in late winter and early spring when natural daylight is limited. If you start seeds indoors well before the last frost date, artificial light usually gives better results than relying on a windowsill.
Tips
Leggy seedlings are a sign that light is too weak or too far away. Keep fixtures secure and cords arranged safely around watering areas. Pair good light with moderate temperatures to encourage sturdy growth instead of soft, stretched stems.
General guidance for US gardens. Timing depends on your local frost dates and hardiness zone. Page updated Aug 4, 2026.