Peppers, Hot & Sweet
Capsicum spp.
Family Solanaceae
Warm Season Crop
This crop certainly has had a wild trip around the world. Originally from the Americas, chiles have become important to cuisine all over the world. Capsicum plants originated in modern-day Peru and Bolivia, and have been a part of human diets since about 7,500 BC. They are one of the oldest cultivated crops in the Americas. Origins of cultivating chili peppers have been traced to east-central Mexico some 6,000 years ago, although, according to researchers at the University of California Berkeley in 2014, chili plants were first cultivated independently across different locations in the Americas including highland Peru & Bolivia, central Mexico, and the Amazon. They were one of the first self-pollinating crops cultivated in Mexico, Central America, and parts of South America.
Peru has the highest variety of cultivated Capsicum diversity because it is a center of diversification where varieties of all five domesticates were introduced, grown, and consumed in pre-Columbian times. The largest diversity of wild Capsicum peppers is consumed in Bolivia. Bolivian consumers distinguish two basic forms: ulupicas, species with small round fruits including C. eximium, C. cardenasii, C. eshbaughii, and C. caballeroi landraces; and arivivis with small elongated fruits including C. baccatum var. baccatum and C. chacoense varieties.
When Europeans first encountered these plants, the best word they could produce for them was “pepper” relating to the black pepper (Piper nigrum), an unrelated plant with pungent flavor that you probably well know as the ingredient companion to table salt. The word chile comes from the Nahuatl word (chilli) for the same thing.
Very quickly these plants were brought all over the world, due to colonization and trade, including almost immediately to China. One species, Capsicum chinense, was named such because when European botanists were exploring the flora of China, they came across a chile that appeared to be native. But it was introduced to China by the Portuguese in the late 1600s or early 1700s and had already naturalized. Chiles have naturalized in many tropical parts of the world, often distributed by birds who love the fruits and are unaffected by its spiciness.
Worldwide, there are five domesticated species of chili peppers, though there are about 43 species of Capsicum:
Capsicum annuum is the most well known pepper in the world and includes many common varieties such as bell peppers, wax, cayenne, jalapeños, Thai peppers, chiltepin, and all forms of New Mexico chile.
Capsicum frutescens includes tabasco, malagueta, labuyo, piri piri, and kambuzi.
Capsicum chinense includes the hottest peppers such as the naga, habanero, Datil and Scotch bonnet.
Capsicum pubescens includes the South American rocoto peppers.
Capsicum baccatum includes the South American aji peppers.
The substances that give chili peppers their pungency (spicy heat) when ingested or applied topically are capsaicin (8-methyl-N-vanillyl-6-nonenamide) and several related chemicals, collectively called capsaicinoids. The quantity of capsaicin varies by variety, and depends on growing conditions. Water-stressed peppers usually produce stronger pods. When a habanero plant is stressed, by absorbing low water for example, the concentration of capsaicin increases in some parts of the fruit.
When peppers are consumed by mammals such as humans, capsaicin binds with pain receptors in the mouth and throat, potentially evoking pain via spinal relays to the brainstem and thalamus where heat and discomfort are perceived. However, birds are unable to perceive the hotness and so they can eat some of the hottest peppers. The intensity of the "heat" of chili peppers is commonly reported in Scoville heat units (SHU), invented by American pharmacist Wilbur Scoville in 1912. Historically, it was a measure of the dilution of an amount of chili extract added to sugar syrup before its heat becomes undetectable to a panel of tasters; the more it has to be diluted to be undetectable, the more powerful the variety, and therefore the higher the rating. The modern method is a quantitative analysis of SHU using high-performance liquid chromatography (HPLC) to directly measure the capsaicinoid content of a chili pepper variety. Pure capsaicin is a hydrophobic, colorless, odorless, and crystalline-to-waxy solid at room temperature, and measures 16,000,000 SHU.
Capsaicin is produced by the plant as a defense against mammalian predators and microbes, in particular a fusarium fungus carried by hemipteran insects that attack certain species of chili peppers, according to one study. Peppers increased the quantity of capsaicin in proportion to the damage caused by fungal predation on the plant's seeds.
Sweet peppers are peppers that have been selected to lack the pungency naturally found in most Capsicum species. There have been sweet varieties of peppers selected for thousands of years, before colonization. Most sweet peppers are selections of Capsicum annuum, but other species have been selected for less pungency (spiciness). There is even a rather new habanero pepper that has been bred without spiciness, which is pretty cool because underneath all that heat are some complex flavors that, for most, get lost under the barrage of heat exhibited by the habanero.
USES
From ancient civilizations to modern food science, pepper has played a crucial role in extending the shelf life of perishable foods. Its use as a preservative dates back to ancient times, where it was prized for its ability to prevent spoilage and maintain the quality of food during long journeys and harsh climates. Especially before refrigeration, in warm-tropical climates, plants like chiles were depended upon for preserving food. Whereas in colder climates where one can have a root cellar and where temperatures didn’t get so hot for so long, such spices were less heavily depended upon. This may explain why cultures closer to the equator tend to exhibit more flavorful and engaging spices.
Humans have evolved to enjoy the burn of the chile pepper, some to an almost masochistic degree! But it isn’t just the spiciness of peppers people are attracted to. Chiles host a range of great flavors, and their breeding exhibits this range of flavor.
Chili pepper pods are botanically berries. When used fresh, they are most often prepared and eaten like a vegetable. Whole pods can be dried and then crushed or ground into chili powder that is used as a spice or seasoning. Chilies can be dried to prolong their shelf life. Chili peppers can also be preserved by brining, immersing the pods in oil, or by pickling.
Many fresh chilies such as poblano have a tough outer skin that does not break down on cooking. Chilies are sometimes used whole or in large slices, by roasting, or other means of blistering or charring the skin, so as not to entirely cook the flesh beneath. When cooled, the skins will usually slip off easily.
The leaves of every species of Capsicum are edible! Yes, though you’ve probably been told that nightshade plants have poisonous leaves, this is not true of many, maybe even most nightshades. Pepper plants, along with tomato and eggplants, have edible foliage. The leaves of pepper plants, which are mildly bitter and nowhere near as hot as the fruit, are cooked as greens in Filipino cuisine, where they are called dahon ng sili (literally "chili leaves"). They are used in the chicken soup tinola. In Korean cuisine, the leaves may be used in kimchi. In Japanese cuisine, the leaves are cooked as greens, and also cooked in tsukudani style for preservation.
GROWING
SEASON & PLANTING
Peppers are warm season crops in our region and in warm microclimates, they are perennials. In fact, peppers aren’t just domestic plants in our region. They are native. The chiltepin plant (Capsicum annuum var. glabriusculum) can be found throughout canyons in the borderlands of Arizona and has an ancient history of use.
You can start seeds indoors or in a greenhouse early, or obtain starts from savvy nurseries, and protect the young plants from frost to get an early start.
You can also start plants in the monsoon season for a fall crop that will last until frost, if we get a frost. This is called a “second season” crop. It has become more popular as the summers have gotten hotter, and as gardeners have gotten creative instead of just following old fashioned planting guides.
Peppers tend to hold themselves up well, but some varieties may need staking.
SOIL & NUTRITION
Peppers are a fruiting crop, and fruiting usually takes more nutrition than just growing, so prepare the soil with lots of organic material. If you grew crops in your garden bed in the winter, you will need to freshen up your bed. Feed plants throughout the season with a general purpose organic fertilizer.
As it gets hotter in the season, you will be watering more often. Our water (whether you use city water or have a well) tends to be a bit alkaline. So the more you water, the more alkalinity tends to build up in the soil. You can counter this by adding gypsum to the soil, or acidifying your water with epsom salt or vinegar. Bringing the pH of the soil down will help plants continue fruiting. The buildup of alkalinity can lock up phosphorus and other nutrients, though pepper plants aren’t nearly as sensitive as tomato plants are.
TEMPERATURE & SUN EXPOSURE
Grow peppers in full to part sun. Avoid reflective heat. The more sun, the more fruits. But also, the more sun, the more care (watering, feeding, managing pH). Peppers will grow until frost kills them. Many people will protect and treat peppers as perennials. They are much easier to perennialize than tomatoes and can live for many years.
WATER
Water regularly, but don’t keep plants water-logged.
HARVESTING
Different peppers are harvested at different times, depending on what is wanted. Many peppers are harvested when they are green, but many people want the color as peppers often change color as they ripen. Generally, you can harvest the fruits whenever they are the ideal size.
WILDLIFE
The tomato horn worm is a common “pest” of the pepper. We usually grow enough peppers at our house that we don’t worry too much about them. Plants will come back from being fed upon. But if you don’t have enough plants to share, identify other nightshade plants you can transfer the caterpillar to (Datura, ground cherries, wolfberry, wild tobacco, and other nightshades).
INVASIVENESS
Peppers are not only not invasive, they are native plants. The domesticated varieties don’t tend to escape cultivation.