Starting your seeds indoors will lessen the amount of time you have to wait to see results in your garden, and many people prefer to grow their plants indoors first to ready them for the growing season. It can be motivational and help to relieve your spring fever a bit.
If space is available near a sunny window, start seeds four to eight weeks before the plant-out date in your area (average date of last killing frost). Starting too early usually results in spindly plants due to crowding and lack of sufficient light. Lighted plant carts are great for seed starting.
Almost any container with drainage holes in the bottom will work for planting. Paper milk cartons cut in half, Styrofoam cups, tin cans, plastic trays and pots are common containers used. For convenience, however, you may wish to start plants in the plastic trays and pots available at garden supply centers.
Use a rich, well-drained soil. Potting soils made for African violets and other house plants usually are suitable and do not have weed seeds. They are, however, more expensive than soil mixes you can make at home and often contain chemical fertilizers. I find the best mix for starting seeds is 1 part sphagnum peat, 1 part perlite, and 1 part vermiculite. You can get all three of these in almost all garden centers, and make 3 – 4 times more growing medium for the price you’d pay for the premixed soils.
When mixing your own seed starting mix, the sphagnum peat may contain a few weed seeds or fungal spores, this is not a big problem and is easily combated. Place the soil mix in shallow trays or baking pans in an oven for 45 minutes at 250 degrees. For best results, the soil should be moist. After the soil has cooled, fill containers firmly but do not pack. Allow about 3/4 inch from the soil surface to the rim of the container. Place seeds on the soil surface. Use a piece of window screen or old flour sifter to sift soil over the seeds to the depth indicated on the seed packet.
If you use compartment trays or individual peat pots, place two or three seeds in each pot. Do not cover too deeply, as this may reduce or prevent seed germination. Just like planting directly in the ground, a general rule is to cover no more than four times the diameter of the seed. Apply a fine spray of water to avoid washing the seed, causing them to float to the soil surface.
Cover the containers with plastic sheets or panes of glass and place in a cool room (60 to 65 degrees) away from direct sunlight until germination. By doing this, you will almost eliminate the necessity of watering the bed again before the seeds germinate. Be sure to keep an eye on it though. DON’T let it completely dry out! Germination can take anywhere from a few days to a couple of months, depending on what you are growing.
When seeds germinate, move them gradually into brighter light. When the seedlings have developed the first true leaves, thin to one plant per container if using partitioned trays or peat pots. Always leave the strongest looking seedling to grow, this is also a good time to give the seedlings a drink of compost tea diluted so it looks like weak sun tea, I use 1 cup compost tea to 10 cups water for my seedlings first feeding. Use tweezers to pinch off unwanted seedlings rather than pulling them, to avoid disturbing the remaining seedling.
Water your seedlings carefully. Small containers used for starting plants dry out quickly. On the other hand, soil kept soaking wet inhibits seedling growth and may kill the plants. After the first feeding with dilute compost tea, or other organic fertilizer, it is not necessary to give them another feeding until they are planted in the ground. Feeding too much before planting in ground usually ends up with tall spindly plants.
About one week prior to planting-out time, start hardening-off your seedlings by gradually exposing them to longer periods outdoors unless temperatures are below 50 degrees. Always start hardening-off in the shade and slowly move the plants to a brighter location for the first few days of this process, by the third or fourth day the seedlings should be in full sun during their time outside. At the same time, reduce watering to a minimum as long as plants do not wilt. This will help the plants adjust to full exposure without undergoing undue shock at planting time.
When it comes time for planting in the ground, carefully remove the plant from its container keeping the roots intact. Dig a small hole in the garden plot and place the plant into the hole. Cover up the roots completely nearly up to the bottom leaves of the plant. Pack down the soil around the plant and water.