Sweet Peppers - Seeds to Success

Sweet Pepper

Capsicum annuum

Quick Facts

Plant family: Solanaceae (Nightshades)
Season: Warm
Life Cycle: Annual
Transplant to first harvest: 55-75 days

History

Solanaceae-plant-family — Figure 1. Sweet peppers belong to the Solanaceae plant family.

Peppers or chiles, are members of the Solanaceae family , also known as nightshades, which includes crops such as the Irish potato, tomato, tomatillo, and eggplant (Figure 1).

Peppers are likely native to the Oaxaca region of Mexico, where they are referred to as chiles, with evidence dating back to 5000 B.C. Peppers were also widely produced in Guatemala, and evidence of this crop’s presence in Peru was documented in 1609. They were transported by Spanish and Portuguese explorers and adapted to many different climates. Columbus discovered pungent (hot) peppers in the West Indies and coined the name “pepper.” By the 16^th century, peppers were introduced to Europe, but were not commercially produced in the southern U.S. until 1925.

Map-showing-the-origin-and-migration-of-sweet-peppers-to-the-U.S. — Figure 2. Map showing the origin and migration of sweet peppers to the U.S.

In Europe, pepper is dried to make the spice paprika, and in Mexico and Portugal this crop is essential in many staple culinary dishes. Peppers are also very important in Louisiana for Cajun and Creole cuisine as a member of the “Holy Trinity,” along with onions and celery. Peppers are an essential ingredient in dishes like gumbo, jambalaya, etouffee, and stuffing.

Pungency (heat) in pepper fruit is concentrated in glands located in the placenta, the inner white tissue that supports the seeds. Capsaicin is an odorless, colorless, and flavorless alkaloid responsible for pungency in peppers and is measured in Scoville Heat Units. The pungency (heat) of peppers ranges from zero to two million Scoville Heat Units: bell peppers rate zero, tabasco pepper ranges from 500-2,500, and the ghost pepper measures 855,000-1 million.

The main ingredient in Louisiana hot sauce, cayenne pepper, is the same species as bell pepper. Other common peppers used for hot sauce are tabasco and Habanero peppers, which are another species.

Varieties

Peppers can be broadly divided into sweet or hot types. The main types of sweet peppers are (1) bell and (2) frying (see Figure 3). Hot pepper types include poblano (ancho), cayenne, jalapeño, and others (e.g., Anaheim, habanero, serrano); but only recommended varieties for these types will be covered at the end of this section.

bell-and-frying-peppers — Figure 3. Main types of sweet peppers are bell and frying.

Sweet bell pepper fruits are traditionally block-shaped, lobed, and range from 4-12 inches long. The fruit’s first stage of ripeness is generally green and glossy but it continues ripening to either red, orange, yellow, brown, or purple at the mature fruit stage. The seeds and stem are removed from the harvested fruit and the flesh is eaten. Sweet frying peppers have a smaller width and a more tapered (elongated) shape. A common frying variety is the Cubanelle, a Cuban pepper that is very flavorful and common in Caribbean island cooking.

Peppers have either open-pollinated (including heirloom) or hybrid varieties. Some peppers are heirloom varieties, like the giant Marconi and Sweet Banana, meaning the seeds have been saved for at least 50 years, can be saved each season and replanted, and are open-pollinated. Peppers produce perfect (containing both male and female parts), mostly self-pollinating flowers. If saving seed, different varieties need to be separated by a distance of 300-1,600 feet to prevent cross-pollination. Generally, it is not recommended to save seed from fruit for future planting with hybrid varieties as they are usually not expressed properly in the next generation.

It is recommended to select disease-resistant varieties whenever possible. In Louisiana, the hot and humid climate may increase risk for disease and pest pressure in pepper plants. This may cause fruits to fail to reach full maturity or ripen past the green stage. See the recommended sweet pepper varieties for Louisiana in Table 1.

Recommended hot pepper varieties for Louisiana include: Poblano (Ancho), Long Red Cayenne, Red Thick Cayenne, Super Cayenne, Jalapeño El Rey, Garden Salsa Jalapeño, Inferno, Jalapeño, Mitla Jalapeño, Mucho Nacho Jalapeño, Tam Mild Jalapeño, Tormenta Jalapeño, Anaheim Chile, Hatch Chile, Big/Giant Chile, Habanero Caribbean Red, Charleston Hot, Red Cherry Bomb, Chilly Chili, Santa Fe Grande, Habanero, Hildago Serrano, Hungarian Hot Wax, Mariachi, NuMex, Serrano, Thai, and Tabasco.

When and How to Plant

Peppers are warm season, frost-sensitive, tropical perennials grown as an annual in Louisiana. Pepper seeds should be started inside 6-8 weeks before the desired transplant date (refer to the Sweet Pepper Planting Guide, Table 2). Using seed germination trays (with at least 1.5-inch diameter cells), plant 1 seed per cell at a shallow depth, about 1/8-inch deep, just deep enough to be covered with a thin layer of soilless potting mix. Seeds will germinate best in a well-lit area in soil temperatures between 65-95 degrees F (optimum germination temperature is 85 degrees F). It is essential to keep the soil moist, which usually requires daily light watering. A seedling heat mat and plastic dome lid are helpful in maintaining ideal germination conditions.

Pepper plants easily survive transplanting, but seedlings are susceptible to cold-shock and growth may be stunted if soil and air temperatures are too low. Aim to transplant outside when soil temperature is 65-95 degrees F (there should be no danger of frost) and ideally during a cloudy day to reduce wilt. The use of a soil temperature map can help guide planting decisions. A few days before planting transplants outside, it is recommended to follow a hardening-off process to transition seedlings to outdoor conditions. Refer to the Sweet Pepper Planting Guide (Table 2) for the recommended spacing when transplanting. If space allows, it is recommended to plant two rows per raised bed to increase the leaf canopy cover, which decreases the risk of sunscald.

As a warm season crop, peppers are sensitive to cold temperatures below 50 degrees F and hot temperatures above 90 degrees F. Bloom drop and a reduction in fruit size may occur in temperatures over 95 degrees F. The optimum growing conditions are warm days (80-90 degrees F) and cooler nights (65-70 degrees F). The expected growing season for peppers is 13-15 weeks.

Table 2. SWEET PEPPER PLANTING GUIDE

Category	Transplant Outside Dates	Spacing (inches)			Days to Harvest*
		Plants	Rows	Beds
Sweet Peppers	North LA: April-May 15; July-Aug 15 South LA: March 15-May 15; July-Aug 15	12-18"	36"	1-2 rows, 6-12” apart in 30-40” beds	90-100 days (55-75 days)

*First range of days: seed to first harvest; second range of days in parentheses: transplant to first harvest
Note: Table adapted from LSU AgCenter, UF Extension Planting Guides and Southeastern U.S. Vegetable Production Handbook

Where to Plant

Since peppers are a warm season crop, well-draining, warm soil and full sun (at least 6 hours/day) are required. Pepper plants prefer a soil pH between 5.5 and 6.8, are sensitive to a low pH, but will tolerate heavier soils. It is recommended to plant peppers in box beds or in traditional raised garden rows that are about 12 inches tall to ensure good drainage. In all types of gardens, it is recommended to add a layer of compost, peat moss, rotted hay, or other organic matter and mix into the soil to optimize plant health. This is especially important for pepper plants, as they thrive in soil high in organic matter.

Reflective plastic mulch — or a plastic fabric/film — is recommended to deter aphids that transmit viruses, increase soil temperature, and control weeds. Drip irrigation is also recommended when using plastic mulch to maintain ideal soil moisture and to encourage productive plants.

Each season, rotate plant families — avoid planting crops from the same plant family in the same area of the garden — to reduce disease and pests. A longer crop rotation is recommended for Solanaceae crops to reduce pest pressure and risk of disease.

Plant Care

Watering

Check for adequate soil moisture every 2-3 days. The soil should remain moist but take care not to oversaturate, as this encourages blossom-end rot. Drip irrigation helps to meet the high-water demand for this crop, which is especially important during the fruiting stage. Deep watering is important to encourage a more extensive root system. If plants are stressed for adequate water, this will significantly impact pepper production.

Fertilization

Blossom-end rot is the most common nutritional disorder of peppers. A dark, leathery, sunken patch on the part of the fruit furthest from the stem, it develops when calcium is unavailable to the plant. Often, the soil has sufficient calcium, but the gardener is not watering frequently enough to keep soil calcium dissolved and available for root uptake. If the disorder continues after watering problems are corrected, conduct a soil test and discuss results with a local county extension agent.

Organic fertilizers such as compost, fish emulsion, composted poultry litter or manure, worm castings, and blood or bone meal originate from living organisms. They are far more environmentally sustainable and safe than traditional synthetic fertilizers. They naturally release nutrients more slowly and over a longer period of time. When applying organic fertilizer, it is important to use in unison with compost, cover crops, and crop rotation, which all work together to build soil health. Learn how to convert inorganic fertilizer recommendations to organic fertilizers here.

Alternatively, a synthetic fertilizer may be used at a rate of about 1.25 pounds (2.5 cups) of 13-13-13 for every 25 feet of row or 75 square feet. Broadcast, or sprinkle evenly, over the soil and then mix in about 3-6 inches using a rake. Supplemental sidedressing, or reapplication of synthetic fertilizer, is recommended when the first immature fruits are visible. Sidedressing is the addition of fertilizer to the soil around already established plants when the plant begins to fruit or vine, primarily to provide nitrogen. When using synthetic fertilizer, sprinkle 2 tablespoons around each plant, keeping it about 6 inches away from the plant stem; water into the soil. Because of their slow, steady release of nitrogen, crops fertilized with organic fertilizer do not usually need to be sidedressed, but fish emulsion is a good, quick-release source of organic nitrogen for sidedressing if needed.

Support

example-of-staking-and-securing-pepper-plants — Figure 4. Staking and securing pepper plants.

Pepper plants must be staked to support the fruit; this will also optimize yield and fruit quality. Drive 2- to 3-foot wooden stakes that are 1-inch wide into the ground (about 10 inches deep) before transplanting at the recommended plant spacing intervals (about 12 inches apart). One transplant should be planted beside each stake and secured to it using garden or butcher twine. When the plant reaches 12-15 inches tall, tie it to the stake with a loose loop to prevent future stem girdling. Continue securing the plants to the stakes for every 12-15 inches of growth. See Figure 4.

For extra support, the Florida Weave Technique may be used in addition to individual pepper plant staking, though this method may not be sturdy enough to replace staking entirely. For the Florida Weave Technique: place a metal T-post at the end of each row and one in the middle; then place squared wooden stakes between every few peppers. When the plants are 12-15 inches tall, use garden or butcher twine to run line on each side of the row of plants (about 10 inches above the soil) and tie the twine to the stakes (do not zig-zag string between plants, as they are tender and breakable). In this method, the plant is never tied to the twine or stake. It’s recommended to do one more level of twine when the plants have grown another 12-15 inches, about 10 inches above the last support weave. Watch this helpful video tutorial on the Florida Weave System (skip to 5:20 for pepper-specific trellising).

Weeds

Plastic mulch will control most of the weeds; hand-pull weeds close to the plant, especially in the planting holes. Pepper plant roots grow at a shallow depth, so take care using hand tools to weed.

Insect Pests and Diseases

Aphids and thrips are common insect pests for pepper plants and can transmit harmful viruses. Peppers are susceptible to viruses (e.g., tomato spotted wilt virus, tobacco mosaic virus, and potato virus Y), fungal diseases (e.g., Phytophthora root rot and anthracnose), and physiological disorders (e.g., blossom-end rot and sun scald). Many pepper varieties are resistant to specific diseases, and these should be selected and planted — especially if the garden has been afflicted by one or more diseases in previous growing seasons. See Table 3 to aid in diagnosis and management of some common pepper insect pest and diseases. Common prevention and management methods include removal of plant debris, crop rotation, and increased air circulation.

Table 3. Organic and Natural Management for Common Pepper Insect Pests and Diseases

Symptoms	Diagnosis	Organic and Natural Pest Management
• Wet, humid conditions • Sunken spots on fruit, with pink spores	Anthracnose	Plant resistant varieties, select against red and yellow fruit varieties Crop rotation (3 years) Avoid working in fields when plants are wet Mulch; avoid overhead irrigation Regular harvest; remove diseased fruit Organic/natural fungicides
• Curled and yellowed leaves • Stunted crops • Sticky honeydew on leaves	Aphids (green peach, melon)	Timely planting and harvest Reduce water stress Weed control Use water jet to dislodge Reflective mulches, insect barrier fabric Beneficial insects: lady bugs, lacewings, predatory stink bugs, syrphid flies Insecticidal soap, neem oil, pyrethrin, Azera
• Warm, humid conditions • Small yellow-green, water-soaked spots on lower and older leaves • Older spots become brown-black with yellow halo • Yellowed leaves; defoliation • Blossom drop and yield loss	Bacterial leaf spot	Plant resistant varieties Avoid overhead irrigation Avoid working in fields when plants are wet Reduce plant stress Use copper-based fungicide sprays
• Green-yellow or black sunken spot on bottom of fruit • Premature fruit ripening • Calcium deficiency • Drought stress, root damage • Over-irrigation, high humidity	Blossom-end rot	Plant resistant varieties Keep soil pH at 6.0 to 6.5 Fertilize (abundant calcium) and mulch Adequate, consistent irrigation, avoiding very wet/very dry cycles If soil is calcium deficient: drench soil around plants with calcium solution; remove fruit
• Small, irregular holes in leaves • Concentrated damage in young plants and seedlings • Stunted plants; reduced yield	Flea beetle	Timely planting Perimeter trap cropping (radishes) Super Light Insect Barrier or AgroFabric Pro to protect transplants Crop rotation Reflective mulches Beneficial insects: parasitic nematodes Insecticidal oil, spinosad, pyrethrin, Azera
• Small yellow larvae • Tunnels inside leaves with white trails	Leaf miners	Row covers Beneficial insects: parasitic wasps Remove infected leaves Spinosad
• Active June-August • Maggots exit at blossom end; tiny round holes • Oval brown pupae inside fruit • Premature ripening or fruit decay	Pepper maggot	Yellow sticky cards (3×5”) attract flies that lay the eggs; attach to small wire stakes near soil Perimeter trap cropping (cherry peppers); spray or remove pests with vacuum
• Wet soil at plant base • Late summer, early fall • Stunted plants; off-color • Plant wilt and death	Phytophthora root rot	Well-draining soil; add compost Plant resistant varieties Remove diseased plants
• Aphid-transmitted • Leaf streaking, mottling • Stunted plants; yield loss	Potato virus Y	Plant resistant varieties Reflective mulches Trap cropping, weed control Remove infected plants, control aphids
• Girdled stem • Plant wilt and death • Soil warming in spring • White fungal growth; mustard seed-like structures at plant base	Southern blight	Remove diseased plants and topsoil Crop rotation with non-host crops to reduce levels
• Overexposure to sunlight • Thin foliage canopy; defoliation • Drought stress	Sun scald	Plant varieties with thick foliage Thick foliage canopy or shade cloth
• Mottled (mosaic), light and dark green foliage • Stunted plants • Uneven fruit ripening; yield loss	Tobacco mosaic virus	Plant resistant varieties Reflective mulches Remove diseased plants immediately
• Black, irregularly shaped lesions on leaves • Discolored or lesioned fruit • Stunted plants; wilt • Transmitted by thrips	Tomato spotted wilt virus	Plant resistant varieties Weed control; reflective mulches Avoid growing ornamental bedding plants with pepper transplants Remove diseased plants immediately
• Transmitted by whiteflies • Yellowed and distorted leaves • Stunted plants; small leaves; bushy appearance • Reduced yield; blossom drop	Tomato yellow leaf curl virus	Plant resistant varieties Manage whiteflies; cover plants with floating row covers Weed control; reflective mulches Remove and discard infected plants immediately
• Leaf discoloration and wilt • Tiny white flies flutter when plants are disturbed • Sticky honeydew on leaves • Black, sooty mold fungus	Whiteflies	Regular monitoring of plants Crop rotation Insect netting (50+ mesh) Beneficial insects: lacewings, parasitic wasp, predatory mite Insecticidal soap, neem oil, Beauveria bassiana

Note: Table adapted from LSU AgCenter; Texas A&M AgriLife Extension; Alabama A&M and Auburn Universities Extension; and UMass Extension Vegetable Program. The Louisiana Pesticide Law regulates the use of pesticides in schools to protect children and staff from harmful exposure to chemicals and is enforced by LDAF. The recommended alternative to routine pesticide use is Integrated Pest Management (IPM), which combines pest control, disease management techniques and organic/natural alternatives, many of which are found in this table.

Harvest and Storage

Peppers may be harvested at any stage of ripeness, usually marked by color from dark green to red, yellow, orange, brown, or purple. The fruit should have reached mature size and be firm and glossy. Harvest the fruit by hand using harvest/pruning snips to clip the stem of the fruit from the plant.

Peppers are usually harvested every week for at least 3-5 weeks, or until fruit production stops. The fruit is bruised easily and should be handled with care postharvest. Fruit will continue to ripen postharvest; storing at room temperature will speed up this process.

Harvested peppers should be stored in the refrigerator and are best consumed within 5-7 days. Ideal storage temperatures for peppers are 45-55 degrees with high humidity (90-95%). In these conditions, peppers will hold for 2-3 weeks. Take care not to store peppers below 45 degrees F, as they are cold sensitive.

Preserve peppers by freezing or canning.