The serious seed starters have been busy for weeks. Back in January, the most dedicated of gardeners began cleaning containers and planting seeds beneath elaborate light systems, complete with bottom heat to give seedlings an extra boost. These gardeners preordered their seeds before Thanksgiving, and have completely planned this summer’s garden. Then there’s the rest of us.
For those who were otherwise occupied in January (perhaps munching leftover holiday cookies and thinking ahead only to snowy days, not green ones), all is not lost. We still have plenty of time to start seedlings indoors.
Growing plants from seed is one of the most satisfying of all gardening pursuits. Gardeners can select exactly the plants they’d like to grow and can often save money by starting seeds. Mid-March is the perfect time to start seeds for plants that need eight to 10 weeks of growing time before the last spring frost, including tomatoes, peppers, marigolds, zinnias and a hundred others.
By planning now, the gardener can order seeds, gather the needed supplies and set up a light system to provide the optimum conditions. It doesn’t take a lot of equipment or money to start seedlings indoors. Here’s what you need to get started:
Recycled containers are fine, such as flats left over from last year, but they must be thoroughly cleaned before use with a bleach/water solution (one part bleach to 10 parts water). If you wouldn’t eat out of the container, it’s not clean enough!
Drain holes are a must in any container used to grow plants. If you’re purchasing new containers, look for seed starting flats that come with clear covers to hold in moisture for the first week or so.
• Soil-less mix, also known as seed-starting mix
Selecting the right mix is the most important step to successful seed starting. Make sure the mix is a soil-less mix, which is composed of peat moss, perlite and vermiculite. Peat pellets are also ideal for starting seeds.
Potting soil should never be used, because it can harbor fungal pathogens that cause “damping-off,” a fatal disease of seeds and seedlings. Once seedlings are infected with damping off, the stems turn brown and the seedlings wilt to ground level, then die. Spend the few extra dollars to purchase a high-quality soil-less mix.
The sky’s the limit when it comes to seed choices. Print catalogs and websites offer an incredible diversity of seeds. Garden centers and hardware stores are also filled to the brim with vegetable, flower and herb seeds for this year’s garden. Many gardeners save their own heirloom seeds from year to year, so check with friends for some pass-along gardening treasures.
Read seed packages carefully (or consult a trusted reference, such as The New Seed Starter’s Handbook by Nancy Bubel) for important instructions for the seeds you’ve selected, including how early to start and any special needs, including temperature or light.
Because supplemental light is a must for indoor seed starting, many gardeners set up grow lights in the basement. The brightest, sunniest window can’t come close to mimicking the light levels in a greenhouse. Additional light can be supplied by using a fluorescent shop light.
Standard fluorescent bulbs will suffice; just be sure the plants are no more than 3 inches from the light as they grow. Putting light fixtures on chains will help in adjusting the lights. Artificial lights should be on for 13 to 16 hours. A timer will make sure the plants get the amount of light they need as well as some darkness each day.
Not planning on using extra light? Seedlings will be weak and spindly without it.
Take care not to over-water seedlings, since this can promote damping-off. Plants should never share drain water, because the damping-off pathogen can move from plant to plant through shared water. Water should be untreated; use a bypass or bottled water if you have a softener.
Seeds contain all the nutrients needed to get a plant started. Once the first set of true leaves have emerged (the first leaves to appear are the “seed leaves,” then come the true leaves), seedlings will need added nutrients. Some seed starting mixes contain slow-release fertilizer. If yours doesn’t, water in a balanced, water-soluble fertilizer (10-10-10).
About 10 days before moving plants outdoors (around the beginning of May), gradually acclimate the tender seedlings to outdoor conditions, a process known as hardening off. To harden off your seedlings, cut back on water and fertilizer, and gradually move plants to a protected location outside.
Be sure to do this gradually, because bright sunlight or drying winds can easily turn tender green seedlings brown in a single day. Be sure to protect the seedlings at night until all threat of frost has passed. In mid to late May, seedlings can be planted outdoors in the garden.
Think ahead to flowers and vegetables you’d like to harvest from the garden this summer, then spend some time this month gathering supplies. In July, you’ll enjoy the fresh, healthy produce and gorgeous flowers even more, knowing you raised the plants from seed.
Denise Ellsworth directs the honeybee and native pollinator education program for the Ohio State University. If you have questions about caring for your garden, contact her at 330-263-3700 or click on the Ask Denise link on her blog at www.osugarden.com.