What Does It Mean to Germinate Seeds for Planting?
- Nearly every plant begins from a seed, which contains a plant's embryo. Germination is the point at which a plant begins to grow from the seed. The seed provides the embryo with a food supply and the genetic information it requires to grow into the same plant as its parents. Until germination, seeds are dormant, with the embryo absorbing oxygen, giving off carbon dioxide and gradually using up its stored food. The seed waits for the ideal conditions in its environment to germinate. When the ideal conditions exist, the seed breaks dormancy and germinates. Growth usually begins when water causes the embryo to swell and break the seed open.
- Gardeners must provide the ideal conditions for germination. To germinate, a seed must have four elements: The seed must be fresh and undamaged, and it must have the correct temperature, moisture and air levels for its particular variety. A gardener's first step is to select a well-draining potting medium designed specifically for germinating seeds. The medium should be rather fine in texture, loose and free of insects, disease organisms and weeds. Select containers with drainage holes in the bottom. Iowa State University Extension recommends cleaning containers with warm, soapy water and rinsing with a diluted bleach solution of 1 part bleach to 9 parts water. Slightly overfill containers with the soil, then gently scrape off excess soil with a board or knife. Moisten the soil by watering carefully; let excess water drain away. After sowing the seeds, mist containers with water and cover them with plastic wrap or a plastic bag to keep moisture in. Remove the covering when seeds germinate.
- Temperature influences the rate of germination.temperature goes up image by Nataliya Litvinova from Fotolia.com
Providing adequate moisture is the first step in germination, since water makes the embryo plant swell. However, seeds need a moist, not soggy, environment or they can rot. Allow the soil surface to dry between waterings. Temperature affects the speed of germination. The closer the temperature is to optimum, the quicker seeds germinate. The Iowa State University Extension says most seeds germinate when the soil temperature is between 68 and 86 degrees Fahrenheit. Seed packages state what temperatures are best for germination. - Respiration in dormant seeds is low, but they do require some oxygen, and respiration increases during germination, North Carolina Cooperative Extension Service says. This is one reason why the medium that seeds are sown in must be loose. If oxygen is limited or cut back during germination, germination can be slow or stopped entirely. Air circulation also helps to ward off diseases. Some seeds need light to germinate, but many do not; some need periods of light and dark. Seed packages state light requirements. Also, follow planting-depth directions on seed packages, as seeds planted too deeply may not have enough energy for the fledgling plant to reach the soil surface.
