Choosing the Right Light

Make Sure Your Seedlings Get the Light They Need

Our SunLite Tabletop Garden is compact, yet there's plenty of room for seedstarting or growing light-loving plants.

Gardeners are typically a thrifty lot. This is especially true when it comes to seedstarting equipment. Though I'll spend $30 on a special peony variety or $150 on granite stepping stones, the grow light setup that I use for seedstarting is a comical collection of ancient shop lights and a rickety, homemade stand. When February rolls around, I wrestle the various pieces from barn to house and spend a couple hours putting the whole contraption back together for another year of service.

My light setup is effective, but it isn't very attractive, so I usually hide it away in our guestroom upstairs. I've tried putting it in the basement, but in late winter the temperature down there is only about 50 degrees. That's too cold for good germination, and I also lost a lot of seedlings to damping off. Our second floor is cool—usually no more than about 65 degrees F.—which is a good temperature for seedlings. My peppers and tomatoes would probably germinate much more quickly if they were in a warmer spot (or if I used a heat mat, but I've found that seedlings get leggy if the air temperature is any warmer.

Whether you're a cheapskate like me, or have wisely invested in a modern, high-quality indoor light garden, here's what's most important when it comes to growing seedlings under lights:

Intensity. Seedlings get leggy when they don't receive enough light. Light intensity is determined by the wattage of the bulb and by how close the bulb is to the plant's foliage. Regular incandescent bulbs aren't used for growing seedlings because they give off too much heat and will burn tender foliage. Fluorescent bulbs are ideal for seedstarting because they give off very little heat, so can be positioned a mere three inches from your seedlings. As your seedlings grow, you should adjust the height of your fixtures to keep the bulbs no more than three to four inches away from the foliage.

Color Spectrum. Seedlings grow best with a good balance of red and blue light—as close to the full-spectrum of natural sunlight as possible. This keeps the plants growing rapidly, yet they stay stocky. Full-spectrum fluorescent bulbs are your best choice for seedstarting. Penny-pinchers can use a combination of one cool white and one warm white bulb, purchased from the local hardware store.

Duration. For best results, seedlings need 14 to 18 hours of light each day and at least 8 hours of darkness. Whatever kind of indoor grow lights you have, put them on an automatic timer. It's a very smart investment.

It would be great to have an attractive, well-built light garden that I wouldn't need to hide in the basement or a back bedroom. One with easily adjustable fixtures, full-intensity, full-spectrum fluorescent bulbs, water-tight shelves, casters and an automatic timer. I could keep it right in the living room and visit my seedlings before and after work. Maybe this year!

If you have any tips and techniques to share, we'd love to hear from you. Write to us at: innovativegardener@gardeners.com