Your
YARD AND GARDEN

Sow seeds indoors for healthy transplants

Dave Robson

March is considered an ideal month to sow seeds indoors for starting your own transplants. Look at most seed packets. They generally indicate to start plants eight to 10 weeks before transplanting outside in May. It's better to end up with a shorter transplant than try to hold a taller one.

Most homeowners use houseplant soil for starting seeds. Packaged mixes are satisfactory as long as the material is sterilized. If the mix isn't sterilized or the package has been opened, sterilize the soil by placing the moistened soil in a metal pan for 30 minutes in a 200-degree Fahrenheit oven. An old meat thermometer should register between 130 and 140 degrees.

Cooking soil will smell. Place it inside a roasting bag to limit odors.

Packaged houseplant soil should be loose and well-drained if used. If it isn't, add an equal volume of peat moss, vermiculite or perlite.

Some gardeners report success using individual peat pots for starting seeds. A common type is the Jiffy-7 pellet, which looks like a cookie but expands into a little pot when wet.

Make sure you don't allow the Jiffy pots to dry out; likewise, avoid setting them in water.

Seeds need uniform moisture to germinate and grow. Water only to maintain a moist soil, never soggy or saturated.

Once seeds have germinated and are established, you might be able to reduce the amount of water needed. Do so carefully to avoid wilting the seedlings. Once wilted, most seedlings never recover.

It's a toss-up which is more important: temperature or light. Both are related and dependent on the other.

Soil temperature is crucial for seed germination. Ideal temperature is 75 degrees Fahrenheit. However, the air temperature for seedlings should be 65 degrees.

Setting the seed flat on top of the refrigerator can supply some of the bottom heat needed. However, the seeds can sometimes be forgotten.

Once seeds have germinated, keep the air temperature on the cool side. In fact, lower temperatures usually produce a shorter, stockier and healthier transplant. Night temperatures can be as low as 55 degrees. Day temperatures should not be above 65 degrees. It's tough keeping the temperatures on the cool side when humans occupy the same space as plants.

Light is important for growth. Seedlings need at least 14 hours of bright light each day. Setting the plants in a south window helps, but temperatures may be too warm and produce vigorous, but spindly, growth.

Plants can be placed under lights. Make sure plants are close enough to receive the maximum benefit, but far enough away to prevent burning.

Plants should be placed no closer than 6 inches and no farther than 12 inches from fluorescent bulbs. For incandescent types, keep plants 12 inches away, but closer than 24 inches. Tall, lanky seedlings with a large distance between sets of leaves indicate temperatures too warm or not enough light.

Avoid fertilizing transplants indoors unless growing conditions are ideal. Wait until you transplant them outside.

David Robson is an Extension Educator, Horticulture, at the Springfield Extension Center, Cooperative Extension Service, University of Illinois. You can write to Robson in care of Illinois Country Living, P.O. Box 3787, Springfield, IL 62708. Telephone: 217-782-6515. E-Mail: robsond@idea.ag.uiuc.edu

18 ILLINOIS COUNTRY LIVING • MARCH 1997