Fluorescent, grow-light bulbs provide the needed red and blue light frequencies for plant growth. Bulbs will last for two seasons and are readily available as “plant and aquarium lights.” Shop light fixtures are the most effective, especially the 4-foot fixture with a metal back that reflects the light back toward the plants. They can be hung from adjustable chains. If you use long, fluorescent plant bulbs (40 watts), the fixture needs to be placed within inches of the plants

Compact fluorescent grow-light bulbs (CFL) are available as blue (~6500K) and red (~3000K) spectrum bulbs. Either 65 or 85 watt bulbs are sufficiently bright, but be careful that the seedlings don’t get too close or the leaves will burn.

LED lights are twice as efficient as fluorescent lights. They use four times the energy of a large CFL but produce eight times the light. One high-intensity LED fixture (300 watts) costs about $13 per month to operate 16 hours a day. The fixture can be placed 18 inches above the plants.

To start seedlings indoors, begin with 12-14 hours of light (especially blue spectrum) while the plants are sprouting and developing leaves.

Use a timer to automate the chore of turning the lights on and off. Select a timer that has a three-pronged, grounded cord because you are using it around water.

Once moved outdoors, plants need 6-8 hours of sunlight.

Plants that don’t get enough light will show signs of etiolation, or tall, spindly growth that searches for the sun.

Light Sources

4-foot shop light fixture, long fluorescent bulbs (Phillips Soft White for Kitchen and Bath T8; Phillips Daylight Deluxe T8), single bulb clamp fixture: Home Depot
Compact fluorescent bulbs, blue (~6500K) and red (~3000K) spectrum: BulbTown.com
High-intensity LED fixture (300 watts): Galaxyhydro (amazon.com)