Some people like to sprout their seeds on damp paper towels placed in a warm location for a few days, then transplant the sprouts into a container to grow. While this method works, there is the risk of damaging the tender sprouts as they are transplanted. Instead, most people prefer to sow seeds directly into a small container. Your choice of containers depends on how many seedlings you want to start, your available space, and preference.
Peat pellets. These are expandable discs of dried sphagnum peat moss that expand when they are soaked (see picture #2). To prepare dry pellets, place them in your growing tray, then gently pour water over them and allow the pellets to soak. They should be fully expanded within about 5 minutes. Before sowing your seeds, pour off any excess water in the tray. Otherwise, the moistened peat may be too wet and reduce your germination rate.
One of the major drawbacks of peat pellets is their tendency to retain too much water and/or dry out too quickly because of their small size. Peat pellets will likely have to be gently watered every day, but be careful not to let your seedlings get waterlogged or soaked. Also, because they are so small, seedlings grown in peat pellets will probably need to be potted into larger (2" or 3") pots before going outside. On the bright side, the shock of transplanting is reduced because you can bury the seedling complete with the peat pellet, so the plants roots are never directly disturbed.
Peat pellets, however, are relatively inexpensive and easy to use.
- Plastic trays. If you're growing a lot of seedlings, consider using the same kind of blister pack trays that professional growers use. These trays can hold dozens of seedlings each, are easy to transport, and are very inexpensive. To use them, fill the tray with a potting medium, then sow the seedlings into the individual containers. One downside to these trays is that the seedlings will need to be transplanted when it's time to plant, which is a shock to young plants.
- Jiffy pots. Jiffy pots are small fiber containers made from formed sphagnum peat moss (see picture #1). They have the consistency of cardboard and easily soak up water. Because they are available in larger sizes, seeds can be sown directly into Jiffy pots that are then transplanted directly into the ground. They are also less likely than peat pellets to dry out or become saturated by watering mistakes. On the other hand, Jiffy pots will still likely need to be watered daily or every other day. Also, the walls of Jiffy pots can form a barrier to new root development after the young plant is transplanted into its permanent home. To prevent this, cut off the bottom of the pot during transplanting so roots can escape into the surrounding soil.
Once you've decided on your container, fill the containers with the soil of your choice (unless you're using a peat pellet), and then sow the seeds. Seeds should be sown according to the direction on the packet. Most seeds are sown 1/8 to 1/4 inch deep and covered loosely with damp soil. You can either sow the seeds onto the soil surface and then cover to the proper depth with moistened potting soil or perlite (recommended), or you can poke small holes in the surface and gently insert the seeds, then fill the holes back in.
After you've sowed your seeds, cover the container with plastic or a clear dome. This will hold in moisture and keep the seeds warmer. Most seeds will need to be kept warm and slightly moist to germinate. In general, temperatures between 70º and 80º are ideal for most seeds, although this might vary depending on the seed. Always check the package directions. Seedlings typically take between a few days and a few weeks to germinate. Once they've germinated, they will poke through the soil and begin to rapidly grow.