Learning Your A, B, Seeds
A few tips on starting those special plants indoors, and getting a jump on spring.
BOSTON — I grew my first plant from seed in kindergarten. Each child was given three bean seeds, soil, and a Dixie cup. Every morning, we would rush past the teacher, Mrs. Hitch, to the windowsill to check the beans' progress.
The slender, pale-yellow shoots that appeared were miraculous, and so fragile. How could something that small ever become Jack's beanstalk of storybook legend?
My attachment to seeds has changed little. I still wonder at the energy stored in a single seed, the power to take root, the starchy food that nourishes a plant's beginnings. But most of all, I wonder if my dinky, balky, undernourished little seedlings are ever going to grow into the mammoth plants of seed-catalog legend.
It takes real commitment to start a plant from seed. In spring, local nurseries set out vigorous plants of tomatoes, zinnias, herbs, and lettuces in six-packs for about what it costs per seed packet.
Don't forget Costoluto Genovese
So why bother with seeds ? It's a question even experienced gardeners ask themselves every winter. And the answer is: exclusivity. We're garden snobs. Why buy common tomatoes when you can grow classic heirloom Costoluto Genovese tomatoes from Italy? Why settle for average sunflowers when you can grow Inca Jewels?
Nurseries can't afford to raise and stock large numbers of unusual varieties. So it's up to gardeners to grow their own. And if you are growing in quantity for a vegetable patch, starting from seed probably will save you money.
If the gardener is determined to get a jump on the season by starting seeds indoors, he or she should know a few things first. We asked Roger Swain, science editor of Horticulture magazine and host of PBS's "The Victory Garden," for his tips on getting the most from seeds.
Mr. Swain points out that seeds are living organisms. Once exposed to oxygen and water, they "get busy metabolizing." The general rule is, the warmer the air temperature, the faster they metabolize and send up shoots.
While there are many helpful gadgets and gizmos that make indoor seed-starting more glamorous, the basic components are straightforward, Swain says.
Start with fresh seeds -those that have been packed for 1998 have a guaranteed minimum germination rate.
Know the date of your area's last anticipated frost, and work backward from there in determining when to start seeds indoors. Gardeners who "get all itchy-twitchy," Swain says, wind up with leggy, overgrown plants that become squatters in the house because it's too cold to transplant them outside.
Buy a good seed-sowing medium. Most seed-starting formulas, also known as "soil-less" mixes, have a peat base and are fairly sterile. (Ordinary garden soil can harbor microorganisms that attack young seedlings.)
Find a container with good drainage. You can use a plastic flower pot, seed flat, or even the bottom of a milk carton with holes poked in it, but if you recycle a plastic container from year to year, sterilize it with a solution of one part bleach to nine parts water to prevent "damping off," the term for a fungus that causes seeds to decay or seedlings to collapse.
Sow the seeds as directed on the package. But Swain has a suggestion: If the seed is as big as a tomato seed, cover it with 1/4-inch of soil. But if it is as tiny as a petunia seed, don't cover it at all.
Set pot in a few inches of lukewarm water and allow the water to wick up. Once the soil has absorbed the moisture, take the pot out. You shouldn't need to water again until the seeds sprout. But the surface should not be allowed to dry out. To keep moisture in, use a clear plastic cover, or Swain recommends cutting a layer of newspaper to exactly fit the top of the pot. Remove the newspapers or covers once the seedlings break the surface.
Most seeds need no light to germinate, but they do need warmth - 70 to 80 degrees F. will make them sprout quickly. Some gardeners put seed flats on top of the refrigerator.
One gardener places them in his gas oven with the pilot light on, but we don't recommend this unless you don't do much baking.
After a week or so (or many weeks, in the case of some perennials), a fragile little white shoot emerges from the soil. Congratulations. The real work has just begun. The seedling needs immediate relocation to the light. Swain recommends direct light from south-facing windows instead of fluorescent lights or "grow lights," but either will work. Grow lights provide a wide spectrum of light, which is required by plants such as African violets in order to bloom. "Seedlings need all the light you can give them," he says, "the spectrum is unimportant."
Swain says a common mistake made by indoor seed growers is to misjudge the light intensity. As you move farther from the window, the amount of light may look the same, but the quality is dramatically reduced. A better solution, Swain says, is to set seedlings no farther than one foot from the sill.
First leaves aren't the real thing
Now that the sprouts have emerged, a good seedling wants its nursery bright and cool - ideally, says Swain, 50 degrees F. at night, 70 degrees in the day.
Don't wait too long to move seedlings to larger quarters. When they develop their first set of "true" leaves, it's time to pot them up in something larger. (Generally, the first leaves on a new plant are not the real thing - on tomatoes, the first true leaves are actually the second set.)
At this time, Swain says, it's important to begin watering with a soluble fertilizer - which can be a MiracleGro or a fish emulsion. (If you are like me, it's better to give the plants a little diluted fertilizer of one-quarter strength each time you water, instead of trying to remember to do it full-strength once a month.)
Another Swain tip: To encourage vigorous seedlings, mimic the effect of wind by running your hand lightly over the seedlings once a day. Swain says it won't make weak plants stronger, but it can't hurt, either.
After transplanting, give plants a day to recover out of full sun. You can water from the top now, but only when the surface is dry, and avoid wetting the leaves. If your plants have what looks like algae growing on the soil, or whitish, powdery blotches on the foliage, Swain suggests an emergency remedy - sprinkle a powdered form of sulfur lightly over plants and soil, which should halt fungi growth.
When the weather has warmed up and the danger of frost is past, your plants are ready to move outside, but do it gradually - a process known as "hardening off." Swain says that plants need to be hardened off because of the increased exposure to ultraviolet light, which can burn them. Start plants in the shade for a few hours the first day and gradually increase their exposure until they can handle full sun. Old hands recommend moving plants into their new home on a cloudy, windless day. And be sure to keep them well watered.
When growing seeds indoors, success is a mixed blessing. My plants persevered despite green slime, rough handling, and drying out - although they never looked as good as the ones in the catalog.
And I had more Lemon Gem marigolds and cosmos than I could hope to use. Roger Swain says the beauty of seed-grown surpluses is that you can share them. Or trade with other gardeners who have that bean plant of your youthful dreams.