Where to start?
What seeds do you want to plant and grow in your garden is the first question. Then measure the garden space and plan what plants will grow where and how much room they will need. Determine how much you want to plant because a typical tomato seed packet contains 25 seeds. Determine where you are placing the planted seeds in your home.
Needs
Containers can be cell trays, peat pots, compressed seed pellets, egg cartons, dixie cups. Seed starting potting soil is the best to use because of its light well drained mix. Light is needed at germination, so the seedlings have energy to grow. A bright window may do but seedlings may get “leggy” stretching for light. Grow lights are ideal as they can be 4”-6” from the seeds and moved away as they grow. Remember in March or early April, daylength is still short.
Temperatures of 65 to 75 degrees are ideal for seed germination. If your home is cooler, than a heat mat under the containers will keep the soil warm for germination. Temperatures can be 5 to 10 degrees lower after they sprout. Water needs to be checked daily. Seeds need to be moist but never wet. Covering the seed tray with a plastic cover will give the seedlings a greenhouse effect and supply the humidity they also need. Air circulation is also important.
Sowing Seeds
Most vegetable seeds can start to be sown six weeks before our Chicago area last day of frost, which is May 15. Seed packets also list the number of weeks seeds should be sown before last frost, in this case use May 15th and count backwards, that will give you the time to sow. Planting depth is listed on the seed packets. A general rule on depth is four times as deep as the width or twice the thickness of a seed. When sowing multiple varieties of plants, make sure to tag them on what they are.
Problems
Fungus gnats, damping off, little root growth is from too wet of soil. Check the seedlings every day for water, light, air circulation to avoid any issues.
Prepare the seeds for outdoors
This is called “hardening off.” The plants are “soft” because of growing indoors with consistent light, air, temperature, and water. Once outside they will have more intense light, wind, fluctuating temperatures, heavier watering. They need to gradually adjust to the wind, humidity, temperature, and moisture changes. Two weeks before planting in the garden starts the process of bringing them outdoors in a dappled shade, a gentle breeze helps to make the seedlings stronger. A few hours at start increasing the time every couple of days. Check the soil for watering needs.
Seedlings can be planted in the garden when the air temperature is above 55 degrees and soil temperature is 50 degrees. If seeds are small, they can be protected by cut plastic bottles, support stakes, mulch. Fertilize when outdoor growth begins with NPK numbers in the 3 to 5% range. This will result in some very fresh and tasty vegetables.