Peppers (Capsicum) require a temperature of no less than 50 degrees Fahrenheit just to survive. To set fruit and thrive, both sweet and hot chillies generally need a temperature range between 75 to 85 degrees Fahrenheit. If you live in a cooler climate and have an outdoor garden, it can be difficult to keep your pepper plants warm enough. Beyond bringing potted plants indoors, you can use a few key processes that provide the warmth they need to produce an abundant harvest.
Position black plastic mulch over your growing area or planting container, and cut an "X" shape for each pepper plant so you can insert the plants through the holes. The plastic mulch absorbs the heat of the sun and helps keep the soil warm.
Fill clear jugs with water, and place them around your plants. The water in these jugs absorbs the heat of the sun and keeps your peppers warm at night when the temperatures drop.
Lay a floating row cover over the tops of your plants in the evening when the sun starts to go down. This lightweight fabric helps keep the environment warmer and serves as a temporary greenhouse. Remove the row covers in the morning so that insects can continue to pollinate the pepper flowers.