Get a Head Start by Starting Seeds Indoors

While we continue to experience a winter wonderland, some home gardeners are thinking about getting a head start by starting seeds indoors. Rosie Lerner, Purdue University consumer horticulture specialist (retired), authored the publication, “Starting Seeds Indoors,” from which I’ll include excerpts.

To do this successfully, you’ll need some growing equipment, an environmentally controlled space, seeds, growing media, and correct timing. While it’s not yet time to start most seeds indoors, some planning and procuring will be needed.

Good seed selection is the first step. “For best results, buy quality seed from a reliable dealer,” said Lerner.

One thing you may wish to try in future years is to save your own seed from heirloom varieties, but this practice requires knowledge of proper techniques. Lerner cautioned against saving seeds from hybrid plants or easily cross-pollinated plants. Likely, these plants would not remain true to the original, and it’s also likely you would end up being disappointed with the results.

Several different types of containers can be used, including wood flats, fiber trays, plastic trays, clay and plastic pots, peat pots, or other containers. “Containers for starting seeds should be clean and sturdy and should fit into the space available for growing plants,” said Lerner.

Several types of growing media can be used, and they can be purchased as a ready-made mix or made from your own mix. Lerner said that the medium used for starting seeds should be loose, well-drained, and of fine texture.

Sterilization of soil and/or other media in the oven may be needed to prevent seedling diseases, such as damping off. Care should be taken not to inadvertently introduce diseases to the growing media after sterilization, as these may actually spread more rapidly than they would have in unsterilized soil. See the referenced publication for more complete instructions.

“The proper time for sowing seeds depends upon when plants may normally be moved outdoors,” said Lerner. “The periods range from 4 to 14 weeks, depending upon the speed with which seedlings grow and the conditions in the home.”

For example, tomatoes may take around 7 weeks of growing time before being ready for transplanting. Cool-season vegetables may allow for earlier transplanting. Pansies and violets may require 14 weeks before transplanting, while petunias require about 10 weeks, and zinnias may only need 4 weeks.

In Whitley County, the average date of the last 32-degree spring frost is around April 22-28. For an extra measure of safety, many like to count on Mother’s Day as the last possible frost. However, even that date is not always safe! Count back from the frost-free date to arrive at the proper indoor planting date for the plants you are growing.

While growing indoors, plants need quality light, proper temperature, timely watering, and fertilization. Special grow lights or fluorescent lights (1 cool with 1 warm white tube) can be used. Grow light technology has advanced much in the last decade, so consider LED lights. A humidifier will help maintain proper humidity. Water so that the soil can dry between watering events, but do not allow plants to completely wilt. Never over-water. A soluble fertilizer can be used at half rate until a few days after seedlings have emerged, then fertilize at the manufacturer’s recommended rate about once every two weeks. In between times, just water.

Before transplanting plants in their permanent outdoor location, plants must be hardened off. This is about a 2-week process of gradually increasing the length of exposure time to the outdoors. Start with short periods each day in shaded locations away from the wind. Do not set outdoors on windy days or when temperatures are below 45 degrees.

For more information, access the referenced Purdue Extension publication at the Purdue Education Store, www.edustore.purdue.edu.