Growing your own seedling transplants saves money and gives you a greater choice of plants than what is available at nurseries. Starting the seeds indoors in early spring before they would normally be planted outside also ensures healthy, strong transplants for your garden. Follow the recommendations on the seed packet for the exact planting time, as it varies between four and 10 weeks for most plant types. A little planning in late winter allows you to grow all the plants necessary for an abundant and attractive garden.
Fill individual seed starting pots with a mix of 1 part peat moss, 1 part compost and 1 part coarse sand. Use plastic seed pots, poke holes in the bottom of small yogurt containers or use plantable peat pots. For a large amount of the same plant, use cell-pack-style pots.
Moisten the soil mix then sow two seeds per pot or cell. Sow seeds to a depth of twice that their width or plant small seeds directly on the soil surface and cover with 1/8 inch of potting soil.
Place the pot in a plastic bag and tie it closed. Place the seedlings in a 68 to 75 Fahrenheit room to germinate---approximately seven to 14 days after sowing depending on variety.
Remove the bag once seedlings appear and move the pots to a sunny window sill where they receive six to eight hours of sunlight. Place under grow lights if no suitable window is available. Place the lights 3 inches above the top of the seedlings.
Thin the seedlings to one plant per pot or cell. Pluck out the weaker seedling once the stronger one has developed its second set of leaves.
Keep the soil moist at all times. Begin fertilizing once the plants are 2 weeks old with a half-strength water soluble fertilizer.
Transplant the seedlings outside once all danger of frost has passed or when recommended on the seed packet. Harden off the seedlings before transplanting by placing them outside for two hours one week before transplanting. Increase the time outdoors each day until they spend a full day outside at the end of a week.