Starting plants from seeds indoors for the garden can be rewarding if you have the know-how and can provide a suitable environment. Otherwise, it may be disappointing. If the seedlings are not healthy and sturdy when planted outdoors, they cannot develop and produce as they should. For example, a tomato plant that should produce 30 to 40 pounds of fruit would provide no more than five to 10 pounds if it gets a bad start.
A lot of gardeners have the idea that seedlings in poor condition can be completely restored to normalcy with a lot of tender loving care. It will not happen.
Of course, you can try to grow them from seed and if it doesn't work out, you can still buy plants from a garden center. At least you will have gained some experience.
Start the seed in one of the new prepared mixes such as Terra-Lite growing media. They are loose and practically foolproof; sufficient oxygen will reach the roots, yet moisture is retained for long periods of time by micro-absorbent action. So both air and water are continually available to the tiny seedling roots.
Sowing seed is an art. Don't cover fine seed such as petunia, snap-dragon, lettuce and carrots, and sow them thinly. Coarse seed can be covered with a loose material such as milled sphagnum moss or one of the ready-mixes on the market.
After the seedlings are up they need good light. Put them near a bright window where they can get sunlight for at least six hours, or under fluorescent lights for 10 to 12 hours per day. Keep the temperature between 70 and 75 during the day and 60 to 65 at night. Water the seedlings lightly each day. When the seedlings develop their second set of leaves they are ready for transplanting to individual pots.
Some seedlings, like cabbage, lettuce, broccoli, larkspur and delphynium, if properly hardened (adjusted gradually to outdoor temperatures), will stand frost and can be planted in the garden three or four weeks before danger of frost is over.
Other plants, such as tomato, pepper, marigold, petunia and impatiens, are tender and should not be planted outdoors until all danger of frost is past. Read the instructions on the seed packets to determine proper timing, allowing for germination as well as growth afterwards.
After the garden is made weed free, this condition is best maintained by not disturbing the soil any more than necessary. Digging can lead to germination of a new crop of week seeds that otherwise would remain dormant.
A large number of small-seed species require moisture and a small amount of red light in order to start the germination process. This is particularly true of weeds that emerge from disturbed soil.
The red wavelengths necessary for germination can penetrate about one inch of sandy soil, thus activating those seeds that were brought nearer the surface by digging.
Grand Rapids lettuce seed, for example, kept moist and in complete darkness, will have germination of only 5 to 30 percent. However, when the inhibited seeds are given a few minutes of either filtered red light or room illumination containing red light, and then replaced in darkness, essentially complete germination occurs.