Start annual flowers and vegetables like peppers, tomatoes and eggplants indoors from seed in early spring for summer blooms or vegetable production, advises the University of Minnesota Extension Horticulture department. The standard guideline directs sowing seeds about five to six weeks before the last expected frost. Start some vegetable and flower plants, such as geraniums, pansies, leeks and onions, fourteen to fifteen weeks before planting outdoors.
Soak the seed-starting mix with water. Let it sit overnight to absorb the water. By the time you use the mix, you want it moist, but not soggy.
Fill a starter pot with starting mix the next day, after the mix feels damp.
Place one to two seeds into the middle of the soil. Follow seed packet instructions to determine how far into the soil to push the seeds. Typical seed packet instructions direct you to push the seeds 1/4-inch deep. Place the soil back over the top of the seeds.
Place the starter pot in a warm location that maintains a constant 70 to 80 degrees F temperature. When seedlings emerge, move the pot to a window with full sunlight or place under grow lights. Turn plants, if placed in a window, so the plant receives sunlight on all sides.
Cut weaker seedlings at soil level with a pair of scissors once seedlings develop leaves. Leave only one seedling.
Harden off seedlings. Place starter pots of seedlings outdoors every day, two weeks before your planting date. Start the plants in a shady location and each day move the pots to a sunny location for an hour. Increase the time in the sun by an hour each day. Bring seedlings indoors at night, before the sun goes down.
Water seedlings daily with a light mist of water until soil appears moist.
Plant seedlings outdoors after all chance of frost has passed and when nighttime temperatures stay at 55 degrees or warmer. Space seedlings according to seed packet instructions.