Follow seed packet instructions thoroughly when starting seeds. Gardeners should pay special attention to seed starting dates, as well as light and temperature requirements, according to University of Illinois Extension. Indoor seed planting times vary from four to 14 weeks from when you intend to plant the seedling outdoors. Starting seeds indoors helps to guarantee a high rate of germination. Seeds started outdoors often experience germination failure from poor weather conditions or rodent exposure.
Spray the seed-starting mix with water until soaked. Let the mix sit overnight. Plant the next morning when the mix has absorbed the water and feels moist.
Pour seed-starting mix into planting cells. Fill cells three-quarters full with mix.
Place one or two seeds into each cell. Push seeds down into the middle of the soil, 1/4 inch deep. Push soil back over the top of the seeds.
Label each cell. Use a piece of masking tape, write the name of the seed planted with a marker and place the tape on the appropriate planting cell.
Set cells in a warm location, one that is between 70 and 80 degrees F. As soon as seedlings emerge, set the cells in a sun-filled window or set under grow lights. If placed in a window, turn plants weekly to give all sides access to sunlight.
Remove weak seedlings from plantings when leaves develop. Cut weaker seedlings at the soil level with a pair of scissors. Cut all seedlings, except one, leaving the strongest seedling.
Harden seedlings. Set planting cells outdoors daily, once within two weeks of expected planting date. Start the cells in a shady location. On day one move cells to a sunny location for one hour. Each day thereafter, give plants an additional hour of sun, increasing to 14 hours of sunlight by the end of the two weeks. Bring cells inside at night and place back outside in the the morning.
Water planting cells everyday with a light spray of water. Soil should appear moist, but not soggy.
Plant seedlings when any chance of frost is past. At this point, nighttime temperatures should average 55 degrees or higher. Follow seed packet instructions to determine seedling spacing.