By Brenda K. Johnson
When you start your own vegetables and flowers from seeds, you have a wider range of varieties to choose from, than from the typical garden center. However, the garden center is a welcome backup if seedlings aren’t ready at planting time.
Growing seeds indoors requires adequate light and moisture, soilless seed-starting mixture in room temperature, and a container with holes in the bottom for drainage. Quality seeds that are stored in cool, dry conditions and seeds less than two years old, provide the highest germination rate.
Some seeds can be directly planted in warm, spring soil or can be jump started for the season as seedlings, indoors. If you are willing to wait for the produce or blooms, direct seed planting has fewer steps. Many garden vegetables and annual flowers may be direct seed planted in soil or containers. These include vegetables such as lettuce, radish, beets, carrots, green beans and squash. Tomatoes and peppers are commonly started as transplants for longer production. Flowers such as marigolds, four o’ clocks, cosmos, and nasturtiums may be planted directly in warm, spring soil or started indoors.
Average frost date for your location and garden seed package information help you decide when to plant indoor seeds. “Farmer’s Almanac” uses the 1981-2010 “climate normal.” Farmer’s Almanac gives April 30 as the last average frost date for the Yankton area, with 50 percent chance of frost after that date.
To confirm this information with a second source, the South Dakota State University state climatologist office uses the “75 percent of the time the last freeze occurred before this date” to arrive at “about the first week of May” as the last frost for the Yankton area. Considering the odds for erratic spring weather, some gardeners add another week or so to that date to set out plants. First fall frost average date is Oct. 5 by the “Farmer’s Almanac” and is the “first week in October” for the Yankton area by the South Dakota climatologist office. Your estimated growing season is the difference between when you plant transplants outdoors and the frost date.
Garden seed packages tell how many weeks ahead of the last frost date to plant the garden. Many transplants are vulnerable to freezing air temperature. Often six-eight weeks ahead the last frost to plant, is suggested. Pre-season exuberance can result in thin, leggy, gray transplants at garden time. Younger plants seem to adjust better to the garden than plants started weeks too early. If you keep the seed package, it will show you when to expect blooms or produce. The first fall frost average date is also important if you decide to start some plants later in the season.
A few simple materials are needed to start plants indoors. Containers can be egg cartons, yogurt tubs or recycled, clean plastic packs in a greenhouse tray, for example. A container should have a hole in the bottom so excess water flows out. Seed starting soilless mixture or potting soil is the growing medium. It’s available locally. Add a little water to the bag for a damp mixture. Better than drafty windowsill light is a fluorescent shop-light on a table. A light timer that is set for 14 hour days, is handy. Chains to keep the light adjusted about 4 inches or so above the plants as they grow, are useful. A clean water spray bottle keeps the soilless mixture surface moist.
Add damp soil to the container nearly to the top. The seed is planted only its diameter deep in soil. A corn seed, for example, is planted less than a half inch into the mixture. Most seeds are much smaller, so a marigold seed is barely in the mixture. After planting, use caution when spraying the surface with the water bottle to keep seeds in place. Keep the surface moist with the spray bottle. If the mixture dries out, set the container in a little warm water to bottom water. When it is damp again, drain the excess water. Seedlings are susceptible to fungi that grow in water-soaked soil. If multiple seeds sprout close together, use scissors to clip stems of less robust seedlings so that hardy seedlings have space to grow.
Seedlings don’t need fertilizer at first, since their energy source is stored in the seed. Once the seedlings have several leaves, apply ¼ strength of a general fertilizer in water no more often than weekly and continue to use water to keep the mixture damp.
If you want more seed-starting information, seed company websites can be resources. For additional information, a resource is at the University of Minnesota Extension: http://extension.umn.edu See “Garden” heading and a post on “Starting Seeds Indoors.” South Dakota climatology information: https://climate.sdstate.edu/tools/frost/ More tips on seed starting: www.hortmag.com “How to Start Seeds for the Best Production.” Free seed-starting class at the Yankton Community Library on March 13 at 1 p.m. or 6:30 p.m. is another information source.