Sweet peppers can be picked when immature or full size, green or red. Hot peppers can be picked at any time for fresh use; hot peppers for drying or pickling should be picked when fully ripe. Pick all peppers before the first light frost.
Most peppers will eventually turn red if left on the vine; some types turn orange, yellow, or brown-purple.
Sweet peppers become sweeter when they change colors; hot peppers become hotter when they change colors. Both increase their vitamin A and C content with ripening.
Peppers continue to ripen after picking; place peppers in a cool place after harvest or they will over-ripen. Peppers will keep one to two weeks after harvest at 50° to 60°F in a moist place.
Harvesting. Use a sharp knife or pruners to harvest peppers. Pulling peppers away from the plant can cause branches to break or tear and leave the plant vulnerable to disease. Leave some of the stem attached to the pepper when cutting fruit.
A good pepper harvest practice is to harvest some peppers to serve green and let others mature to red or full color on the vine to full color. This will give you a mix of flavor, heat, and nutrition. Fully ripe and immature peppers can be served fresh together. Harvest peppers when they are the right size for your use.
Drying and freezing. Hot peppers for drying should be picked when red or orange. Choose only thin-walled peppers for natural drying; thick-walled hot peppers such as jalapeño and serrano will rot before they air dry. (Dry these peppers by smoking.) Air dry hot peppers in a warm place with good air circulation. Peppers can also be dried in a food dryer or on a baking sheet in an oven at 175°F maximum.
Sweet and hot peppers can be frozen without blanching first. Freeze or dry any peppers that you can not use fresh.
Extending the season. Cover pepper plants under plant blankets or plastic spread over hoops when nighttime temperature dip below 60°F or days consistently average less than 70°F. Like tomatoes, pepper plants can be lifted whole from the garden and hung upside down indoors to continue ripening.