Pepper plants can be grown from seed to harvest in containers, but you will need to transplant them from their seedling pots. The good news is that this is a simple process and you can use the same technique for transplanting both sweet and hot peppers. After transplanting, your peppers can be moved around to catch the sun or wait inside during a cold snap. You can pot up any extra peppers to share with friends and neighbors.
Find a pot that is a good size for the mature pepper plant if you will not be transplanting it into the garden later. Hot peppers can be kept in three-gallon pots, but bell peppers will need at least a five-gallon container.
Transplant your pepper seedling after it has at least two sets of true leaves, but before it has outgrown its pot. You can detect this by looking for pale or yellowing leaves and roots growing out of the bottom of the pot.
Fill the new pot three-fourths of the way up with a 50/50 mixture of potting soil and compost. Later in the season you can supplement this with a slow-release fertilizer.
Water the soil in the pot in order to eliminate air pockets. Add a little more soil if it it settles significantly after watering.
Gently squeeze the sides of the pot in order to loosen the plant from the sides of the pots. Peat pots can be replanted whole.
Plant your pepper in the pot. You can plant it at the level of the soil in its previous pot or bury the stem up to the top pair of leaves. Roots will grow all along the stem and provide extra stability for leggy plants.
Water the plant gently, but thoroughly. Check on the plant each day to make sure that the soil is moist, but not saturated.