Capsicum sp.

Peppers are in the genus Capsicum in the group of flowering plants in the nightshade family Solanaceae. Other members of this family include tomatoes, potatoes, eggplant, and tobacco. They are native to the Americas and have been cultivated for hundreds of years. In Connecticut peppers are a frost-sensitive annual vegetable plant that may present some difficulties. The most common species for home gardens is Capsicum annuum which encompass the bell pepper, cayenne, jalapeno, paprika, serrano, and sweet pepper. C. chinense, a species of chili peppers, includes the habanero, Scotch bonnet, Trinidad scorpion, and other hot peppers.

Peppers should be planted in full sun, 6-8 hours per day, and require deeply worked, well-drained soil that has a lot of organic matter. They prefer a pH between 6.0 and 6.8 although they will tolerate a pH as low as 5.5. A soil test from the UConn Soil Analysis Lab will help determine the pH and will give amendment suggestions. Testing and changes should be made in the fall prior to the current growing year so that changes may take effect. Peppers do best in soil that is consistently moist but well-drained. Consider planting in raised beds if soggy soil is an ongoing issue. See Vegetable Garden Basics and Plant Selections for additional information.

When possible, do not plant peppers in a spot where tomatoes, eggplant, potatoes, peppers, or tobacco have been planted within the past three years. Separate these plants as much as possible in the garden and remove or till under all plant residue at the end of the season to reduce overwintering pests or diseases. Members of this plant family can also be planted in deck or patio containers that may be sterilized at the end of each growing season.

Purchase healthy disease-resistant varieties when possible. Pepper seeds may be started indoors 8-10 weeks before transplanting but wait until the soil temperatures reach 65°F before transplanting outdoors (Seed Starting). Direct sown seeds will not germinate in soil below 55°F. Black plastic and row covers may be used to warm the soil but row covers should be removed once plants blossoms are forming as the area under the covers may overheat the plants and cause the blossoms to drop. Nighttime temperature that go above 75°F or below 60°F will inhibit fruit set as will daytime temperatures above 90°F. Even daytime temperatures in the high 80s during fruit set may affect them.Some pepper plant varieties may grow up to 3’ so stake tall varieties of plants. Don’t let fruit touch the ground.

Peppers require 1-2” of water per week. After the soil temperatures have warmed to 70°F apply mulch to prevent weeds, reduce soil borne diseases, suppress weed growth, and retain moisture (this will help control Blossom end rot).

Peppers use phosphorous and potassium for blossoms and fruit. High nitrogen will promote leafy growth but lower fruit yield. Use a fertilizer with a 1-2-1 or 1-2-2 ratio according to your soil test results. See Suggested Fertilizer Practices for Vegetables and Herbs.

Green peppers are actually immature fruit but can be picked when they are 3-4” long and firm. Fruit allowed to stay on the plant will ripen to yellow, orange, red, purple, or chocolate brown. Plant a second row if you want to have both green and mature fruit. Remove or till under all plant debris at the end of the season. Do not compost diseased plant tissues.

• Commonly found on pepper plants are melon or green peach aphids which can vector diseases. See the UConn IPM factsheet Aphids and Viruses.
• Other pests include flea beetle, tarnished plant bug, stink bugs, spider mites, thrips, and European corn borer.
• Pepper maggot.
• Scouting, hand-picking, and low-toxicity insecticides can control many pests.

• Sanitation is key to controlling the spread of disease.
• If possible, peppers should not be planted in the same spot as tomatoes, eggplant, and potatoes for 3-4 years especially if disease was present.
• Cucumber mosaic virus appears as ring spots or necrotic tissue and can be vectored by aphid feeding. Use Horticultural oil or mineral oil to control aphids.
• Tobacco mosaic virus is less of a problem as there are resistant species but can be transmitted by people that also handle tobacco.
• Septoria leaf spot, Anthracnose, and to a lesser extent early blight are fungal diseases that infect pepper.
• Phytophthora capsici is a fungal disease that rots all parts of the pepper plant: roots, stem, crown, and fruit. It will even survive on or in infected seed.
• Bacterial spot is caused by the bacterium Xanthomonas campestris pv. vesicatoria and presents itself as sunken brown tissue on the upper surface of leaves and raised bumps on fruit.  
• Fusarium wilt and Verticillium wilt are common root diseases caused by fungi. Because of soil-borne spores, an important control of these diseases is rotation of plantings of peppers and their close relatives.
• Removal and destruction of infected crop residues and cultural methods that promote rapid drying of wet foliage are also important for control of foliage diseases.
• See the UConn IPM factsheet Minor Diseases of Pepper for additional information.