(Credit: Pixabay)

There is a somewhat questionable line of reasoning that suggests eating something hot makes a warm summer day seem a bit cooler. In this case "hot" refers to the spiciness of the food rather than its temperature. The theory maintains that the pain induced from the consumption of pungent foods causes the human brain to release compounds known as endorphins. The latter have been called the body's natural pain relievers which also are said to induce a feeling of wellbeing.

If there is truth in the preceding philosophy, then there are hot peppers now available to home gardeners that might prompt one to reach for a jacket after eating them. For reasons unclear to the author, each year (mainly amateur) plant breeders take great pride in developing hotter, more fiery peppers. However, the fact is hot peppers are not new as a condiment.

Columbus found indigenous people of the West Indies eating a spicey vegetable. He named it pepper after the spice he was in search of. (Credit: Pixabay)

In his quest to find a shorter trade route to the spice-laden East, Christopher Columbus decided to sail in a westerly direction. The land he first encountered was an island in the Caribbean where he found an unfamiliar vegetable being consumed by the indigenous people. Its fiery taste was reminiscent of black pepper (Piper nigrum), a spice grown in the East Indies that helped prompt his voyage. With the taste connection in mind, Columbus gave the piquant vegetable the name "pepper."

Today, hot peppers are highly regarded on a global basis. Domesticated over 10,000 years ago in the Americas, they continue to bring essential flavor, color, spice, and unique regional identity to plates and gardens on every continent. To acknowledge their importance, the National Garden Bureau has named hot pepper their "vegetable of the year" for 2026.

Peppers belong to the genius Capsicum which is a member of the Solanaceae (nightshade) plant family and was domesticated in Mexico and the Andean regions of South America. Human selection for culinary and aesthetic traits has occurred over the last ten millennia. Continued plant breeding for home gardens and commercial markets has resulted in high-performing, uniform hot pepper varieties.

Hot (and sweet) peppers are consumed on every continent and help create regionally distinctive cuisine. Commercial growers and home gardeners alike share an affinity for this wildly variable crop because hot peppers truly spice up our lives.

The “fire” in hot peppers is caused by the compound capsaicin which is found in the placenta and seeds of hot pepper fruits. (Credit: Pixabay)

The "fire" in hot peppers is due to capsaicin, a colorless, odorless oil-like chemical compound produced by most members of the Capsicum genus. Capsaicin causes a burning sensation when it comes into contact with mucous membranes. It is concentrated in the white spongy membrane (the pith or placenta) inside the pepper fruit. Hot pepper seeds are spicey because they absorb some of the oil when resting against it. Removing the placenta and seeds of a hot pepper will help to tame its fire while preserving its flavor

Sweet peppers contain a recessive gene that blocks the production of capsaicin, making them benign from the standpoint of pungency. Presumably, this recessive gene was the result of a chance mutation in nature that someone discovered and considered to be an improvement to this species.

There are 25-30 known species of pepper, but globally we only cultivate and consume only about five of them: C. annuum, C. baccatum, C. chinense, C. frutescens, and C. pubescens.

Capsicum annuum—This extremely diverse species produces a wide range of sweet and hot peppers in various shapes and sizes. Market classes include bell, snack, jalapeno, and poblano.

The variety ‘jalapeño’ belongs to the species Capsicum annum and is the most widely consumed hot pepper. (Credit: Colorado State University)

Capsicum baccatum—This species is characterized by vigorous plants that produce hot fruits of many shapes. Its flowers are distinguished by a green-yellow corolla ring.

Capsicum chinense—Members of this species produce large plants that bear small but extremely hot fruits, including "super-hot" varieties such as 'Habanero' and 'Carolina Reaper.'

The species Capsicum chinense contains some of the hottest peppers available. Pictured is the extremely hot ‘Carolina Reaper’ variety. (Credit: WikimediaCommons)

Capsicum frutescens—Members of this species produce small, hot fruits, often with more than one fruit per node. The most notable variety of this species is 'Tobasco.'

Capscium pubescens—A bit more cold tolerant than other peppers, this species produces hot, flavorful fruits distinguished by purple corollas and black seeds. This species is most notable for rocoto types of hot pepper and the 'Manzano' variety.

Varieties of the species Capsicum pubescens are noted for their black seeds. Pictured is the variety ‘Red Rocoto.’ (Credit: Falcodigiada)

Growing Hot Peppers

Growing hot peppers is a rewarding, multi-sensory adventure, offering the simple joy of watching vibrant, fiery gems develop in the garden, followed by the satisfaction of adding homegrown "heat" to your favorite dishes.

Because of their sensitivity to cold temperatures and the number of days required for them to mature, it is preferred to use started transplants to establish them in the garden. Those who wish to grow their own transplants should refer to MU Guide 6570 titled "Starting Plants Indoors from Seeds" (https://extension.missouri.edu/publications/g6570).

Peppers of all types should be planted in the garden in the spring, after all danger of frost has passed. They require warmer growing temperatures than tomatoes and typically are planted about two weeks later. Early planting of peppers often leads to poor early fruit set since the latter is hampered at temperatures of 55 degrees F or less. Space plants 12-18 inches apart in rows separated by 24-36 inches. Space plants 12-18 inches apart in rows separated by 24-36 inches.

Peppers perform best with full-sun exposure in a well-drained, loamy soil with a pH ranging from 6.0 to 7.0. Fertilizers with a 1-2-2 ratio (e.g. 5-10-10) can be added to the soil before planting at the rate recommended by a soil test. High rates of nitrogen as a pre-plant should be avoided since it can reduce fruit set. Instead, nitrogen should be added as side-dressing during the course of the growing season, after a significant fruit-set exists.

Since pepper plants have a relatively shallow root system, they are susceptible to moisture stress when rainfall is inadequate. Moisture stress will cause flowers and small fruit to drop. Additionally, it will reduce leaf area, causing the remaining fruit to be sun scalded. Failure to apply adequate water can also exacerbate a physiological disorder of peppers called blossom-end rot.

Peppers are self-pollinated and should set fruit without intervention. As pepper fruits form on the plant, they can add significant weight to the branches. Therefore, a support system of some sort (e.g. stake, trellis or cage) will help prevent branches from breaking and encourage continued fruit development.

Days to maturity vary significantly depending on the species, variety, and growing conditions. A green pepper is ripe when the fruit is no longer growing; a fruit is physiologically mature when it starts to develop color. Promptly harvest fully-grown green fruits or uniformly colored fruits to avoid a reduction in additional fruit set. Use gloves to handle and process hot peppers and avoid touching your eyes.

Hot pepper plants are considered relatively pest-free because they produce capsicum, a natural compound that serves as an effective, plant-derived repellent against many insects and mammals. The following is a list of problems that can occur.

• Bacterial Leaf Spot (Xanthomonas) spreads during wet conditions and, occasionally, via seed. Symptoms appear as small lesions that often have a yellow halo. Removing infected plants and reducing moisture on foliage can help mitigate the spread.
• Phytophthorablight (Phytophthora capsica) is a soil-borne disease that can persist in soils for years. The pathogen can infect almost all plant parts, but it typically infects the crown right at the soil line, causing stem lesions, girdling, and eventual plant death. Removal of infected plant debris and rotation are best practices to avoid infection and persistence in soil.
• Viruses can be transmitted to pepper plants by contaminated seeds or insects. Purchase clean seeds, remove infected plants, and clean garden tools regularly to prevent the spread of viruses.
• Insects such as aphids, white flies, pepper weevils, tarnished plant bugs, and climbing cutworms can cause damage to the leaves and fruits of pepper plants. Regularly scout for insect levels and consider traps or pesticide applications for control.
• Blossom End Rot refers to the pre-mature maturation and rot of fruits. While the underlying cause is calcium deficiency, it is most often the results of inadequate or inconsistent watering as the plant grows.
• Sunscald is a physiological disorder that results from a lack of canopy cover. Fruits have a flat, "burnt" appearance in certain spots and often rot early. Variety selection, trellising and adequate nutrition can help prevent sunscald.

Acknowledgement: Adapted from an article by the National Garden Bureau.

Hot peppers come in many shapes, sizes, and colors. Pictured is the variety ‘habenaro.’ (Credit: North Carolina State University)

Hot pepper fun facts:

Hot peppers belong to the nightshade plant family, making them botanical cousins to tomatoes, potatoes, and eggplants.

Research indicates that capsaicin, the chemical that makes peppers hot, most likely is produced to prevent insect damage and fungal growth within the peppers.

Capsaicin only affects mammals. Birds, insects, and other animals are completely immune.

The capsaicin content of hot peppers is expressed as Scoville Heat Units (SHU's) named in honor of pharmacist Orville Scoville who, in 1912, developed the method of measuring it.

The Guiness Book of World Records lists the variety 'Pepper X' which averages 2.69 million SHU's as the world hottest pepper. In comparison, 'jalapeño' has a "mere" 10,000 SHU's.

Drinking milk eases the pungency of hot peppers because the protein casein in dairy products binds with capsaicin and helps reduce the burn.

One cup of raw red chili peppers contains nearly four times more Vitamin C than an orange.

Eating hot peppers raises your body's core temperature, helping you temporarily burn more calories during digestion.

In 1982, 'jalapeño' became the first hot pepper to go into space on the space shuttle Columbia.