There are several domesticated species of ‘hot’ peppers, most belonging to the Capsicum annum family, each with differing subtypes or cultivars and heat levels.
The intensity, pungency, or hotness of a chile pepper comes from its capsaicin level, which is influenced by type, maturity, and environmental factors.
Native to the Americas, researchers believe chile peppers were first cultivated in southern Mexico. Hot peppers—known variously as chile, chilli, or chili in many sizes, colors, and shapes—are also grown in parts of Asia (China and India dominate), Europe, and Australia.
In North America, Mexico continues to be the region’s top producer; in South America, it’s Peru; and in the United States, California and New Mexico are major contributors to supply with Arizona, Texas, and Florida adding to domestic availability.
Types & Varieties
Chile pepper pungency is measured in Scoville heat units; as a baseline for measurement, bell peppers or Italian sweet varieties, for example, score at zero units on the Scoville scale while habañeros can range from 100,000 to 300,000 units.
Anaheim or New Mexican are among the common milder peppers. They are light, juicy, crisp, and sweet when fresh. Both are cylindrical, up to 8 or 10 inches in length, and have a Scoville heat rating of 2,500 units for Anaheims and up to 7,000 for New Mexican. They are harvested green for fresh use and canning, or red for drying or grinding as an additive to powders and sauces.
Poblano peppers are called anchos when dried. They are flat, wrinkled, and heart-shaped, ranging in color from deep red to almost black with a fruity, smoky flavor.
Immature jalapeños are hot when green but gain pungency and red coloring as they ripen (up to 5,000 heat units). They also increase in sweetness as they mature. These bullet-shaped peppers reach between 2 and 3 inches in length and up to 1 inch in width. When smoked, dried jalapeños are called chipotles.
Serranos are often the easiest pepper to find in the fresh market. Green serranos are available all year, while red serranos are best in the spring and fall, ranging from 1 to 2 inches in length and half an inch in width. Some serrano varieties can be significantly larger in size; heat ranges from 5,000 to 25,000 units.
Hungarian wax peppers are referred to as wax pods due to their shiny appearance. Pods vary greatly in size and shape and are usually yellow when immature. They can be sweet or pungent and used fresh or for pickling. Hungarian wax peppers are closely related to mild banana peppers.
Although available fresh, cayenne peppers are generally ground up for hot sauces. When fresh, cayenne peppers appear wrinkly and may be either deep green or bright red when mature, ranging between 5 and 10 inches in length. The red, mature peppers are hotter than their green counterparts with an acidic flavor.
Capsicum baccatum, or aji peppers, are native to South America with aji translating as ‘chili pepper.’ From amarillo to norteño to panco, aji peppers come in different colors and varying pungency levels from 30,000 to 50,000 units (much like cayenne peppers).
The highly popular aji amarillo, or Peruvian yellow pepper, reaches 4 to 5 inches in length, turns orange when mature, is yellow when cooked, and has a fruity flavor to balance its heat.
Thai peppers are a member of the C. frutescens family. They are small, slightly curvy, and either bright red or deep in color. They seldom grow larger than 3 inches in length and end in a point. Most are quite hot (up to 150,000 Scoville units), though pungency can vary.
Habañeros are fiery-hot, box-shaped small peppers that turn from green to orange, red, yellow, or white when ripe. The red savina habañero is 30 to 50 times hotter (up to 300,000 Scoville units) than the jalapeño. Habañeros are part of the Capsicum chinense family and closely related to Scotch bonnets, for which they are often mistaken.
Rocoto or locoto peppers look like small tomatoes or bell peppers but pack a punch of 50,000 to 100,000 Scoville units. Part of the C. pubescens family, they are juicy and meaty, but like aji peppers, can have fruity undertones.
Chile peppers are warm-season crops that favor well drained soil in raised beds. Crops can be direct seeded or transplanted, with ample irrigation and weed control. Weeds, as well as excess moisture or rainfall, can lead to pathogens and disease.
For harvest, fruit fresh should be firm and skin thick with bright coloring. Peppers should be free from defects such as cracks, decay, or sunburn, and skin should not be shriveled, pitted, or dull in hue.
Fresh market chile peppers are picked multiple times a day during the harvest window; those for drying or processing are less frequent. Lines and striations across the skin can relate to pungency and are not an indication of poor quality.
Chile peppers are harvested by hand and should be rinsed and cooled if for the fresh market. Others may be immediately dried (or smoked depending on the thickness of skin). Pods may be sliced before drying, which shortens drying time and improves color and flavor. Screening and water sprays can remove seeds.
Pests & Disease
A broad range of pests can wreak havoc by damaging seeds, buds and foliage, or the fruit itself, and spread disease from plant to plant or an entire crop.
Aphids, beetles, caterpillars, mites, stinkbugs, thrips, weevils, and worms, as well as fire ants, borers, grasshoppers, leafhoppers, leafminers, mealybugs, psyllids, and whiteflies can harm plants, limit yields, and affect quality.
Chile peppers are susceptible to many diseases and pathogens including anthracnose, blossom end rot, bacterial leafspot, botrytis or grey mold, powdery mildew, and mosaic and wilt viruses.
Viruses are the most significant cause of loss, resulting in underdeveloped fruit and overall lower yields. Soil-related problems such as nematodes, verticillium wilt, and phytophthora rot can also affect plants and yields, and can be reduced through crop rotation, weed control, and soil treatments.
Verticillium wilt is one of the more common soilborne diseases, penetrating plant roots and causing severe wilting of infected plants. Early symptoms include yellowing of lower leaves and stunting.
Phytophthora root rot, commonly referred to as chile wilt, occurs under excessively wet conditions, usually in heavier soil types or low-lying areas. Similarly, bacterial rot is frequently found in warmer, rainy climates, though smaller fruiting peppers are less prone to the disease than larger varieties.
The impact of tobacco mosaic virus has been minimized by new varieties resistant to its effects, which include bumps and discolored areas on leaves, stunted fruit, and uneven ripening.
If present, however, it can be easily spread and remain infectious in debris and seeds for years.