Growing indoor bedding plants for future use in home landscapes gives gardeners the satisfaction of caring for the tiny plants as they mature. Starting seeds indoors before the planting season begins can save considerable money on early summer plant purchases. Most seeds available are hardy varieties that require consistent, basic care to succeed. The success of this endeavor depends on the proper growing medium, warmth and light.
Wash and rinse used plastic plant pots, seed trays and drip trays to remove old dirt, fertilizer and water mineral buildup. Use a mild dish detergent and rinse the containers until the water runs clear.
Find a growing location for your bedding plants inside the house (or greenhouse) that provides northern light. Temperatures should be above 70 degrees F to encourage seed germination.
Fill each individual pot or tray two-thirds full with seed potting mix. This lighter potting mix contains a porous mineral called vermiculite paired with peat moss. Seedling starter mix allows for easy absorption of water and doesn't restrict the growth of tiny seedlings that need to push upward to grow.
Place seeds inside each cup based on individual planting recommendations found on the seed back. Apply a light layer of seedling soil mixture above each seed and water carefully using a watering can. Alternately, water the seeds using a spray bottle to prevent disruption of the soil medium.
Place the seed trays and pots in a warm, dimly-lit location (on top of a refrigerator works well). Within two weeks, most viable seeds will produce a small stem with tiny leaves in the form of a seedling plant.
Position the seedlings 4 to 6 inches beneath growing lamps or fluorescent lights. Seeds require extreme warmth to begin germination. Direct grow lights at the seeds for 16 to 18 hours each day to simulate sun exposure. Schedule a dark period during the night hours.
Water the tender little plants on a regular basis, checking the soil frequently for moisture levels. Add water-soluble fertilizer to your watering can and sprayer. Fertilize the seedlings with every watering by directing fluid towards the tiny roots of the plant.
Adjust the growth lights as the plants grow. Transfer the strongest seedlings to individual pots when the plants reach a few inches in height and have two leaves.
Move the indoor bedding plants outside to a protected area in the shade after the danger of frost has passed. This hardening process allows the seedlings time to acclimate to tougher conditions in a sheltered location. Gradually move the plants into the sun over the course of a week until the plants can be safely moved into the garden.