Growing Hot Peppers - Turn Up the Heat in the Vegetable Garden

Habanero Chili Peppers
Courtesy of the National Garden Bureau

Hot peppers or chili peppers have become even more popular than their sweet relatives. All peppers are in the Solanaceae family, with tomatoes, eggplants, and potatoes. The term ‘hot pepper’ is not a botanical classification. They are often grouped by their fruit shape and/or heat intensity. When a man named Wilbur Scoville first devised a means to test the heat of peppers, his hottest entry then came in at 20,000 units. Habanero and Thai chilies can go as high as 60,000. Compare that to the sweet bell pepper at zero.

It is thought that all peppers, hot and sweet, developed from the wild chiltepin pepper of Central America. The most commonly grown hot pepper variety is Capsicum annum, which includes cayenne, paprika and jalapenos, as well as sweet peppers. The hottest is in Capsicum chinense, which includes Habanero and Thai Chilies.

Although peppers are perennial plants, they are widely grown as annuals. Columbus is credited with bringing peppers back to Spain, as a substitute for true pepper (Piper nigrum).

Botanical Name

Although peppers that score high on the Scoville scale are generally grouped together, there are several pepper species that fall into this category. These include:

Capsicum annum, Capsicum baccatum, Capsicum chinense, Capsicum pubescens, Capsicum frutescens

Common Names

Hot Pepper, Chili, Chile, Chilli

Hardiness Zones

Pepper plants are only hardy perennials in the tropical zones of USDA Hardiness Zones 11 and above. Everywhere else they are grown as annuals. However, it is possible to bring pepper plants indoors, for the winter.

Mature Plant Size

The size of your hot pepper plants will vary depending on the variety you grow and the growing conditions. Most hot pepper plants grow to about 1 ft.w x 2 - 3 ft. h. Some can grow as tall as 5 ft.

Sun Exposure

Hot peppers are heat lovers. They need a spot in full sun, to grow well and to set flowers and fruits. 

Days to Harvest

Days to maturity will depend on the type of hot peppers you are growing and their growing conditions.  Most take at least 55 - 80 days from transplant. If the weather remains cool or if it is an especially rainy growing season, it will take longer for hot pepper plants to begin flowering and ripening their fruits.

When and How to Harvest Hot Peppers

You can keep your plants producing more hot peppers by harvesting regularly, once they reach an eatable size. Many gardeners like to allow their peppers to fully ripen and change color, but ripe fruits tend to lose some of their heat.

Cut the fruits from the plant, don’t pull. Hot peppers are best used within in days of harvest. They can also be canned or frozen.

Suggested Hot Pepper Varieties to Grow

  • "Czechoslovakian Black" - The plant is very ornamental and the tiny fruits pack a punch. Good for drying.
  • "Habanero" - Still the test for a hot pepper lover. There are now several varieties of Habeneros available.
  • "Cherry Red" - Small, round cherry bombs are thick skinned and nice for stuffing.
  • "Hot Lemon" - Lemon in color only, these have a nice balance of heat and flavor
  • "Robustini" - Extremely prolific producers

Hot Pepper Growing Tips

Soil: Hot peppers can adapt to most soil types. They need well-draining soil, so some organic matter should be added. However, they will be hotter if the soil is a bit lean and not overly fertilized. A neutral soil pH of about 6.0 to 6.8 is best. A sprinkling of Epson salts at planting seems to help fruit set, as does crowding the plants in their bed.

Planting: Gardeners zones 8 and above, with long, warm growing seasons, can direct sow peppers once the ground is warm and not too wet. But most hot peppers are either started from seed indoors or purchased as seedlings.

If you start your own hot pepper plants indoors, give them plenty of time to develop. Seed should be started 8 – 12 weeks before your last frost date. The seed can be slow to germinate The use of a heating pad or some other means of heating the soil will speed germination. However, it will also cause the soil to dry out faster and they will need more frequent watering.

You should see the first sets of true leaves within about 6 weeks. At that point, you can transplant them into individual pots and continue growing them indoors.

Before planting them in the garden, be sure to harden off the seedlings. They are very susceptible to cold temperature. Wait to transplant in the garden until after all danger of frost and once temperatures remain reliably above 50 degrees F.

When you transplant, put them in the ground about 1 inch deeper than they were growing in their pots. The base of the stems will send out small roots, making stronger plants. 

Space your plants based on their mature size. Hot peppers do not mind being a bit crowded.

Peppers need warmth (at least 70 degrees F.), to grow and set flowers. However, at extreme temperatures, 90 degrees F. and over and under 60 degrees F., they will drop their blossoms until conditions are more favorable. 

Caring for Your Hot Pepper Plants 

Water: Hot peppers need to dry out between waterings, but make sure they get at least 1 inch of water each week. They will drop their flowers if allowed to become drought stressed

Feeding: Overfeeding will result in leafy plants with few peppers. Add some organic matter before planting, to ensure good drainage. You can also give them a dose of balanced fertilizer at planting time and again when the first flowers appear. Many gardeners add a small handful of Epsom salts to the soil at planting, as a magnesium boost.

Staking: Hot peppers tend to set a lot of fruit all at once. While some varieties are sturdy enough to stay upright on their own, staking may be necessary to keep the fruits from resting on the ground.

Pests and Problems of Hot Pepper Plants

Very few pests attack healthy pepper plants. However be on the lookout for the following.

  • Aphids and thrips can infest older plants. Symptoms include crinkled or very narrow leaves. these insects can spread viruses which have not cure. Destroy any infected plants to prevent spreading the disease. 
  • Cutworms can slice off young plants at ground level. Wrapping the base of the plants with foil, toilet paper tubes, or something similar will thwart them. Even toothpicks on either side of the stem will do the trick.