Success with seeds: starting plants from seed makes economic sense and separates the serious gardeners from the novices

Flower & Garden Magazine, Feb, 2002 by Karen Dardick

You've studied the catalogs, ordered your seed-starting supplies and seeds, and look forward to a bumper crop in summer. But instead of vigorous, healthy plants ready to burst into flower or produce delicious vegetables, you get poor germination, spindly seedlings or weak plants. What went wrong?

Starting plants from seeds really does make economic sense and separates the serious gardeners from the novices. But even experienced gardeners can have frustrating results. I spoke with Renee Shepherd, owner of the specialty seed company, Renee's Garden, to learn her secrets. She's been growing plants from seeds with great success for more than 20 years and helping gardeners across the nation do the same.

The first step is to plant seeds at the right time for your region. Don't start too early. Conventional wisdom on many seed packets advises waiting until danger of frost has passed. But Shepherd believes this is not accurate. She recommends starting seeds six to eight weeks before nighttime temperatures reach into the 50 F range. "It's a more accurate guide," she explained.

Another common mistake is inadequate heat and light. "Seeds require both warmth and light, and many people fail to provide adequate amounts of both," she said.

Heat is crucial for seeds, especially for those with tropical origins, like peppers or impatiens. Many warm-season plants require soil temperatures of 60 F to 65 F for germination. Shepherd suggests using heating mats under seed-starting devices. When seedlings emerge, remove mats and place seedlings under fluorescent grow lights suspended several inches above them. You don't need a timer, as the seedlings will be under lights from just six to eight weeks. This constant light avoids the common problem of spindly plants and promotes healthy growth.

Begin fertilizing when the second set of true leaves emerge. You can use chemical or organic fertilizer according to your own preference, but be sure to feed every three weeks. However, if plants are thriving and growing faster, reduce fertilizer to slow their growth until they can be transplanted in the garden.

You may prefer an intermediate step of transplanting very gently into the next size container usually no larger than a two-inch pot. You can use peat pots which can be planted directly into the landscape or decorative pots if you want to avoid disturbing their roots.

Whatever container you choose, be sure to harden off the seedlings before they take up permanent outdoor residence in your landscape. Do this by exposing seedlings to outdoor temperatures a few hours each day. Gradually increase the outdoor exposure time.

If you want to sow seeds directly into your garden, you can scatter them into the garden effectively by mixing them with a little sand and sprinkling them from a salt shaker. Or place white toilet paper in rows, sprinkle seeds, then lightly cover with amended soil.

Another crucial key to success is thinning seedlings, especially those that have broadcast directly into beds. Even experienced gardeners have trouble removing perfectly healthy plants. But failure to do so guarantees overcrowded plants that can succumb more easily to diseases. Large plants, like basil or squash, can be potted and shared with friends. Edibles, such as lettuce seedlings, can be tossed into salads. And ornamentals can be tossed into the compost pile.

Another key is consistent watering without overdoing it. More seedlings are killed from kindness than neglect. It's better to apply too little water than too much to encourage seedlings to grow strong roots and to inhibit soil fungi. Tough plants do best overall.