Capsicum encompasses hot and sweet pepper varieties, as well as ornamental peppers that produce inedible yet ornamental fruits. While nursery pepper transplants are readily available at most garden centers, it is less expensive and you get a greater variety to choose from if you plant your own capsicum seeds. Capsicum seeds can be finicky about the amount of heat and light they receive, needing the proper amounts of both to germinate and grow healthy.
Fill 3-inch diameter seedling pots with a well-draining potting mixture. Fill a seed flat with 1 inch of water and set the pots into the flat. Drain the excess water from the flat once the soil surface in the pots becomes moist, usually within two hours.
Sow two capsicum seeds per pot, then cover the seeds with a 1/2-inch layer of potting mixture. Cover the pots with a plastic bag, which retains the moisture in the soil until germination occurs.
Set the pots in a warm, 70 to 80 degrees F room to germinate. To ensure the soil stays at the proper temperature, set the pots on top of a seedling heat mat that is set to 70 to 75 F. Heat mats are available at garden centers.
Remove the plastic bag once seedlings emerge, usually within 14 to 21 days of sowing. Lower the setting on the heat mat so it falls between 65 and 70 F and place the seedlings underneath a fluorescent grow light. Adjust the light so it sits no more than 6 inches above the top of the seedlings and leave the light on for 14 to 16 hours a day.
Water the capsicum when the soil surface begins to feel dry to the touch. Water until the soil is just moistened, either by filling the flat beneath the pots with water as before, or by watering carefully from the top.
Thin the seedlings so there is just one capsicum plant per pot once the seedlings grow their second set of leaves. Cut off the weaker seedling at the soil surface, leaving the stronger seedling in place.