It’s easy to buy seedlings, but there are many reasons why you may wish to start your own plants. By starting your own seeds, you have a much greater selection of flowers, vegetables and herbs to choose from. For example, old favorites like hollyhocks and less common varieties of herbs and perennials as well as heirloom vegetables might not be available as plants, or stocks may be limited. Plants with fine seeds should also be started indoors because they can easily wash away in the rain and they may have a difficult time competing with weeds. Starting your own seeds can also help you extend the growing season so you can enjoy a longer, more productive harvest. So why not get started today?
Containers for Starting Seeds
Traditionally, seeds are started in flats or peat pots. There are various sizes of plastic trays, flats, peat pots and the popular Jiffy-7’s available. When moistened, the Jiffy-7 expands to form a small, self-contained pot of soil into which a seed is sown directly. This is an excellent choice when sowing seed of plants that do not like their roots disturbed during transplanting. You might also use eggshells or folded newspaper pots to start your seeds.
It is best to use a light, soilless mix when starting seeds. These mixes are sterile, meaning young seeds do not have any weed seeds to compete with, and there are no harmful bacteria, insects or other pests in the soil right away. Good seed mixes also contain adequate nutrients to carry seedlings through until transplanting. Do not use garden soil, as seeds will not germinate well in the heavy soil, and a fungus disease called damping off is common.
Temperatures for Seeds
Most seeds require warm soil in order to germinate. You will need to heat the soil of the seedling flats with a heat mat. Seed trays can also be placed on top the refrigerator or hot water heater. Do not put seed-starting trays on a windowsill; nighttime temperatures are too cool to allow for good germination. Seeds need consistent warm temperatures of 65 degrees or warmer for optimum germination.
Seed Watering Needs
Seeds need to be kept constantly moist in order to germinate. Moisten the soil thoroughly before planting. Water when the surface is dry with a misting nozzle or plastic spray bottle until the soil is saturated. The medium should be constantly moist, but not soggy. It is important not to overwater, which could drown the seeds and tender seedlings, but also not to permit the flat to dry out.
Seeds should be sown 2-10 weeks before the last spring frost date. Your seed packet will provide this information as sowing dates can vary for different plant varieties or even cultivars of the same plants. Fill your containers almost to the top with moist growing mix. Tamp it down gently and smooth it out. Gently press the seeds into the mix or simply set them on the surface of the soil and place milled sphagnum moss over the top to prevent damping off. Cover the container loosely with plastic wrap or a clear dome, which will help preserve moisture and warmth. Be sure to label your containers with plastic or wood plant stakes and write the plant name and the date sowed. Set trays in a warm spot and check daily to keep evenly moist.
Once seedlings have grown a half-inch or so, you should water less frequently. Let the soil dry slightly between watering, which will help the seedlings stretch and develop a strong root system. Seedlings will also need light and the best method is to use the T-5 fluorescent fixtures or the new energy-saving LEDs. Suspend lights just an inch or two away from the plants. Lights must be on at least 14-16 hours a day. As your seedlings grow, raise the lights accordingly so they do not bump into the lighting fixture. If your seedlings do not get enough light, they will become weak and spindly. Fertilize seedlings weekly with half-strength, balanced, fertilizer. Fertilome 20-20-20 works well. Thin seedlings if they become overcrowded, choosing the healthiest, strongest seedlings to save.
Hardening Off and Planting Out
When the weather is warm, move your seed trays outside gradually over a 5-7 day period. Start by putting them out just for a few hours during the late morning to mid-afternoon, and then gradually increase until they are left out all day and night. Keep them in a lightly shaded, protected spot during the day to prevent sunburn. After a week or two of this transition, gently transplant seedlings into the garden. Try not to handle the root ball too much, as they are quite fragile. Water thoroughly after transplanting and again every day for about a week. Newly set out plants will look sparse at first, but they will grow and fill in quickly, leading to bumper crops and a lush, delicious harvest!