Containers: There are lots of choices for small containers to start your seeds. You can use pots, cell packs, trays, peat cups or pellets, or even eggshells to start seeds. I like to use commercial seed starting trays since they’re inexpensive, come with clear plastic covers, have a reservoir tray for watering from the bottom, and are divided into individual planting cells.
Starting Medium: Use a sterile, soilless seed starting mix made of peat, vermiculite, and perlite rather than garden soil. Commercial mixes are available, or you can mix your own.
Temperature: Most seeds germinate best in soil temperatures around 75° F (24° C). Special warming mats are available for starting seeds in cold sheds, or you can choose a warm spot in the house, such as a warm room, on top of the fridge, or a radiator.
Light: Unless you have a sunny greenhouse, indoor light isn’t bright enough for seeds. The solution is to hang a fluorescent light fixture equipped with full-spectrum (daylight) bulbs about 6” above the seed trays. Adjust the height of the fixture as the plants grow. The lights will need to be on 14-16 hours a day, so a timer comes in handy.
Fertilizer: Once your seedlings are growing, they’ll benefit from a mild fertilizer. Fish emulsion is a popular choice, or use a balanced liquid organic fertilizer mixed at half strength.
Seed Starting Planting Steps
Read on for a step-by-step guide to planting seeds indoors.