Growing from Seed: Part 3

The sooner you can transplant seedlings after they germinate, the better they can survive and continue growing. Delay transplanting your seedlings after they have become crowded and have true leaves, and you’ll get stunting, resulting in slower growth.
    The first green leaf-like structures you see on seedlings are called cotyledons. The cotyledons contain all the energy necessary for germination and the development of the first true leaves. To minimize transplant shock, transplant seedlings soon after the first true leaves appear.
    Small plants grow rapidly, and the sooner you transplant them the faster they grow. Transplant bedding plant seedlings into individual three- or four-inch pots in cell packs such as 804. Metro-Mix, Sunshine Mix, Farfard Mix or Pro-Mix can be used as a transplant medium. These commercial blends have sufficient fertilizer to supply the needs of the transplants for six weeks. Eliminate the need for later fertilizer by blending one-third by volume compost made from lobster or crab waste with the commercial mix.
    Your growing medium must be moist, neither wet nor dry. Using the point of a plant label or the point of a knife, lift each seedling or clump of seedlings from their growing medium. With the same instrument, separate the clump of seedlings into individual plants. Using your fingers, lift each seedling by gently grasping the cotyledon. Never lift young seedlings by grasping the stem. The stem is the permanent part of the plant while the cotyledons are only temporary structures engineered to drop from the stem as soon as the plant becomes well established. If you accidently squeeze the stem, you can permanently stunt the plant’s growth.
    At this point of development, the seedling will require full sun. Minimum temperatures should not drop below 65 degrees. The containers should be irrigated only when warm and dry to a fingertip pressed lightly on the surface of several containers.
    Consider conditioning the plants by placing them outdoors in partial shade for at least a week before transplanting them into the garden.  
    Seeds of cabbage, broccoli, cauliflower, peppers and lettuce should be sown now, from late February through early March. Seeds of tomatoes should be sown approximately five weeks before they are to be transplanted into the garden — unless you desire to transplant tomato plants with tomatoes already attached to the stem.
    A certain amount of pride comes with growing your own bedding plants from seeds.

Coming next week: One-step potting.

Ask Dr. Gouin your questions at [email protected]. Please include your name and address.