An indoor garden provides a great alternative if you don't have yard space for a garden, or the soil in your yard is unsuitable for gardening. Indoor gardening also allows you to keep your plants growing even during the cold winter months. Seedlings from the local nursery may harbor diseases or pests, which can quickly spread to your whole garden. Starting your own seeds for your indoor garden helps prevent these problems.
Plant one seed per small container rather than several seeds in larger containers; using large containers and multiple seeds causes roots to grow together and root damage at transplanting time.
Use containers with good drainage and place them in plastic trays to catch water.
Fill the cell flats or fiber pots with seed-starting mix and water them. The mix will settle down into the pots when you water them.
Add more mix and water again until the containers are full to within an inch of the top.
Plant seeds in your containers to the depth indicated on the seed packets; if unsure, plant four times as deep as the seed's depth.
Place plastic domes over the trays to hold moisture and heat inside. Remove the domes when the seedlings grow tall enough to touch them.
Place your seed-starting trays in a low-traffic area away from drafts. A south-facing window sill may work for a few plants but may be too cold at night and hot during the day.
Place your seed-starting trays on electric mats that are specifically made for seed starting; this keeps the root zone warm enough for germination.
Water the cell flats with a spray bottle or by adding water to the plastic trays and allowing it to soak up into the containers; keep the mix moist, but not soggy, and drain excess water from the trays to prevent root rot.
Use artificial grow lights to provide enough energy for your indoor plants to grow, especially in the winter when the sunlight is weaker.
Keep the grow lights within 4 inches from the top of the seedlings and allow the plants 12 to 16 hours of light and 8 hours of total darkness every day.
Add a water-soluble fertilizer mixed to one quarter of its normal strength after the seedlings have formed three or four sets of true leaves. Don't fertilize more than once a week.
Transplant your seedlings into larger containers once the roots begin to grow out of the drainage holes in the cell flats.
Remove the seedlings gently from the cell flats; hold them by the root ball rather than the stem, because the stems of young plants are easily damaged.