Starting Seeds Indoors
Vegetable Seed Guide
Start a garden early by sowing seeds in containers indoors. Any container that drains well can be used, but many gardeners prefer peat pots or pellets placed in flats or plastic flats with many sections that are sold specifically for the purpose. Either way many valuable advantages will be gained from growing your own plants from seeds. Growing conditions can be controlled, creating plants that are healthier and more robust.
Potting media is important. It can be created by mixing sand, organic compost, fertilizer and sterilized topsoil, or purchasing the commercially prepared varieties. The growing medium should be free of contaminants and drain well, but should have adequate water holding capacity to provide enough water to the roots of plants.
Before planting seeds, fill pots with soil and water well the day before, allowing for overnight drainage. Follow the directions on page 12 for planting depth and distance apart. A good rule of thumb is to plant seeds no closer together than an inch apart. Place a water tight tray under pots and water them from the bottom to avoid damaging new seedlings. Keep about 1/4 to 1/2 inch of water in the bottom of the tray at all times.
Place pots near a window facing south or southwest. If it is late winter hang coolwhite fluorescent plant lights 2 inches above the tops of the plants and raise them as the plants grow. If plants do not have to stretch up to get enough light, their stems will be stronger and will be better able to support heavy fruits and leaves later on in the season. Plants require 12 to 14 hours of light per day.
Cooler temperatures at night will make your seedlings more robust, so maintain at 60° F or below once it’s dark. During the day, maintain temperatures between 70° F and 75° F. Most vegetable seeds will germinate in that range, but peppers, cabbages and tomatoes will germinate faster if kept toward the higher end of the range. To increase heat, use a heating pad on its lowest setting under the tray the pots are in, but be sure to turn off at night.
Thin your seedlings when they are about an inch tall and each have 1 pair of leaves. Use tweezers or small scissors to clip them off at the surface of the soil. This will avoid damaging the seedlings you want to keep. Thin them so that there are no more than 3 strong seedlings per 2 inch pot.
Once plants have formed their first true leaf, fertilize them at each watering with a water soluble plant food that has been mixed with double the amount of water normally used.
Fungi and Insects
Sometimes, soil borne fungi can cause a problem called “damping off”. This occurs when the seedlings get dark at the soil line, fall over and die. If this happens, your soil wasn’t sterile. Always use sterile potting soil for starting seeds. Letting the surface of the soil dry out in between waterings can help prevent this problem also.
If insects should happen to infest your seedlings, a pesticide or insecticidal soap may be sprayed on them, but be sure to follow package directions for seedlings, not full grown plants, or you may damage leaves.
Before transplanting seedlings to the garden, prepare them for the harsher environment by a process called “hardening off”. Reduce the light intensity and the temperature. Leave a longer period of time in between waterings. The easiest way to harden seedlings is to set them outside everyday when the weather is mild for the 2 or 3 weeks prior to transplanting. Water them only when the surface of the soil dries out. Bring them in at night if frost is expected. Make sure they are always protected from strong winds. Another way to harden off seedlings is to put them in a cold frame for a week or two.