Seedlings from Scratch

by Margaret A. Haapoja
Vegetable gardens are back in vogue as families struggle to make ends meet in these difficult economic times. And according to National Gardening Bureau surveys, gardening has been the number one leisure activity in this country for some time. To get a head start on the season, consider producing a few of your own plants this year. The gardener who starts his own seedlings can have exactly the varieties he wants at a fraction of the cost of purchasing the started plants at a nursery or greenhouse.

Seeds are magical, and starting seeds from scratch is a satisfying occupation for housebound growers itching to get their hands dirty. It’s easy. Even a novice can experience the miracle of new life by starting seeds indoors. On cold winter days, gardeners can catch a glimpse of spring under grow lights. In addition to the cost-saving benefits and personal satisfaction to be gained, many useful and interesting flowers and vegetables are only available from seed catalogs. The transplants will be ready at home just when the season and soil are right for planting.

One of the most common mistakes eager gardeners make is starting seeds too early. Tomato plants that are already two feet tall in mid-April in northern Minnesota have been started too soon. These plants will outgrow their space and become spindly. There is no way to slow them down or halt them without doing injury. The ideal is to keep seedlings growing without a hitch until the time is right to set them out in the garden.

Each year I begin by taking inventory of my leftover seeds. Then I plan my gardens and select the vegetables and flowers I want to grow this season. Next, relying on Park Seed’s guide for germination time or the back of the seed packets for maturation times, I count backward from May 27, the average last frost date in the Grand Rapids area. Each plant variety requires a different length of time before it is ready for transplanting into the garden.

I keep a record of the dates I have seeded each variety, and every year I note some seeds that need to be started earlier or later the following season. The following chart shows the approximate time needed from seed to transplant time:

VEGETABLES:
Cabbage, cauliflower, broccoli, Brussels sprouts: 4-5 weeks
Tomatoes: 6 weeks
Peppers: 7-8 weeks
Pumpkins, squash, melons: 2 weeks

FLOWERS:
Geraniuims: 16 weeks
Impatiens: 10-12 weeks
Petunias: 10 weeks
Tall marigolds: 10 weeks
Dwarf marigolds: 8 weeks
Salvia: 8 weeks
Zinnias: 4-5 weeks

For a growing medium, I prefer a pasteurized soilless mix such as Jiffy Mix, Pro-Mix or Peters Professional Redi-Earth. Until I began using this type of medium I was continually plagued by “damping off,” a fungal disease that attacks seedlings causing them to collapse and die. Make sure the mix is well moistened before you start the seeds.

All kinds of containers work for seed starting from special trays sold for that purpose to plastic food containers. Just be sure any container has drainage holes on the bottom to allow excess water to drain away. Depending on the type of seed, it can take anywhere from a few days to two weeks for them to germinate. Marigolds often sprout in five days, but impatiens can take 15 days.

As soon as a seed sprouts, it must have plenty of light. In fact, some seeds—like impatiens and salvia—need light to germinate. Those that need light should be pressed down—not buried—so they make contact with the moist medium. Those that need dark should be covered with about 1 to 2 times the seed thickness and can be placed in a dark place. Ordinary fluorescent light fixtures with a shelf beneath is ideal for germinating seeds. Place the seed trays very close to the lights—4-5 inches—and run the lights 18 hours a day. I use a timer to insure a constant and sufficient duration of light. Windows usually do not provide adequate light and can lead to weak and spindly seedlings. Labels are a must for keeping track of what’s what, too.

The optimum temperature for seedling germination is 65 degrees. Most seeds germinate best at a slightly higher temperature—approximately 70 degrees. A couple years ago I decided to speed up germination of my impatiens seeds and placed them on a heating cable mat. To my dismay, I learned from an expert that I’d cooked the seeds. Impatiens prefer much cooler temperatures and good air circulation to germinate.

Dryness is another major peril for seeds. Once the germination process has begun, don’t allow the seedlings to dry out at all or they will die. Covering the containers with plastic wrap or placing them in a plastic bag until the seeds have sprouted solves the moisture problem.

Sterilize containers to be used for starting seeds indoors before reusing them by rinsing them in bleach water. Since seeds have become increasingly expensive—a packet of blue-eyed daisy seeds from Burpee Seeds is $7.50—it’s important to plant them with great care and save as many as possible to plant next year.

The tiniest seeds—petunias, impatiens, fibrous begonias—may be merely scattered over the firmed surface of the planting medium and bottom-watered without covering. Simply set the pot or container in a pan of warm water and leave it there until the moisture has worked its way to the surface, usually around twenty minutes. The advantage of this method over top-watering is that it does not disturb the newly planted seeds. Among seeds that need light to germinate are petunias, salvia, impatiens, coleus, columbine, dill, lettuce and sweet alyssum. Some seeds need to be nicked or soaked before planting to soften their hard coats. They include canna, hibiscus, lupine, morning glory and sweet peas.

When seeds sprout, remove the plastic bags or coverings and set the seedlings in the recommended light and temperature. While the seedlings are young, keep the soil moist but not wet. I try to water in the morning so the surface of the soil is dry by nightfall—another attempt to ward off the dreaded damping off disease. And I fertilize as I water by adding one tablespoon of soluble fertilizer to a gallon of water.

A plant’s first growth is known as its seed leaves; they are, literally, the leaves that emerge from within the seed. All the later leaves that the plant produces are true leaves. When the seedlings begin to produce their true leaves, I prick them out of their container with a pencil, holding them gently by their leaves—not their stems—and relocate them into individual pots or six-packs and the recommended potting soil.

You can transplant into peat pots which facilitate the final transfer to the garden. I generally use peat pots for squash, cucumbers, pumpkins and melons since these seedlings do not transplant successfully if you disturb their roots. Peat pots are made for this purpose with the intention that they be planted pot and all. Tear peat pots down to the soil level when you set them out, or they will wick moisture into the air and the plants will dry out.

About a week before I intend setting the plants out, I shift them outdoors part of each day, giving them increasing periods of fresh air and sunshine—a few hours at first, lengthening to all day. Such conditioning, called “hardening off,” toughens the young plants.

By starting many annual flowers indoors, you can give them a head start for a longer bloom period, and the special indoor care assures a higher rate of success. Among these flowers are ageratum, fibrous begonias, coleus, impatiens, lobelia, marigolds, pansies, petunias, salvias, snapdragons, verbena and zinnias.

Starting indoors works well for vegetables, too, because the head start brings them into production sooner, and—for cool-loving kinds such as cabbage—enables them to beat the heat. Among the vegetables I’ve started from seed indoors are cabbage, cauliflower, broccoli, Brussels sprouts, cucumbers, eggplant, melons, peppers, pumpkins, squash and tomatoes.