Chilli Pepper

Chili peppers are the fruits of Capsicum plants, members of the nightshade family along with tomatoes and potatoes. They are famous for their fiery heat and are grown and eaten all over the world. You may see the name spelled chili, chile or chilli, depending on where you live.

Chilli pepper Quick Facts

Common name	Chilli pepper
Scientific name	Capsicum
Kingdom	Plantae
Phylum	Tracheophyta
Class	Magnoliopsida
Order	Solanales
Family	Solanaceae
Type	Small shrub in the nightshade family
Habitat	Warm, sunny, sheltered spots
Native range	The Americas
Colours	Green fruit ripening to red-brown; white flowers
Height	About 1.5 m
Edible parts	Hot, shiny berries
Special feature	Hot taste led Columbus to call them peppers

Where the Name Comes From

The word “chili” comes from chilli, a word in Nahuatl, the language of the Aztecs. In the United States people usually say chili or chile pepper, while in Britain, India, Australia, Malaysia and New Zealand they often just say “chilli” without the word pepper.

Origin and History

Chili peppers come from the Americas. People in Mexico and Central and South America were growing them thousands of years ago. When Christopher Columbus reached the Caribbean, he tasted chilies and called them “peppers” because their hot taste reminded him of black pepper, a valuable spice in Europe. In fact, the two plants are not related at all.

After Columbus, traders carried chili seeds around the world. Within about a hundred years they were being grown in Africa, India, China and Thailand, where they became an important part of local cooking.

What the Plant Looks Like

A chili plant is a small, bushy shrub. Most garden varieties grow about 30-90 cm (1-3 ft) tall, though some can grow taller in warm climates. The leaves are smooth, oval and pointed. The small flowers are usually white, sometimes with a green or purple tinge, and each flower has both male and female parts, so it can pollinate itself. Bees and other insects help too.

Each flower turns into a hollow fruit filled with flat, pale seeds. Most chilies start green and ripen to red, though some turn yellow, orange, purple or brown.

Why Chilies Are Hot

The burning feeling comes from a chemical called capsaicin, found mostly in the white ribs inside the fruit that hold the seeds. Capsaicin tricks the nerves in your mouth into feeling heat. Heat is measured on the Scoville scale: a sweet bell pepper scores zero, a jalapeño a few thousand, and the hottest chilies more than a million.

Birds cannot feel capsaicin, so they happily eat chilies and spread the seeds. Scientists think the heat helps protect the fruit from mammals that would chew up the seeds.

Growing Chili Peppers at Home

Sowing the Seeds

Photo by: Koisa Masiwa

Chilies need a long, warm growing season, so in cooler places like the UK or northern US, sow seeds indoors from late winter to early spring (about January to March). The hottest varieties usually take the longest to grow, so sow those first.

Sow seeds on top of damp seed compost, cover them lightly with fine compost or vermiculite and keep them warm, ideally 18-25°C (64-77°F). A heated propagator or a warm windowsill works well. Most seeds sprout in about 7-14 days.

When the seedlings are big enough to handle, move each one into its own small pot, about 7.5 cm (3 in) across. Keep them indoors until all danger of frost has passed, then plant them in bigger pots, a greenhouse, a polytunnel or a sunny, sheltered spot outside.

Watering and Feeding

Keep the soil evenly moist but not soggy, and water at the base of the plant in the morning or evening when it is cooler. Once the first flowers and fruits appear, feed the plants about once a week with a high-potash fertilizer, such as tomato feed.

Temperature and Light

Chilies love warmth and plenty of sun. Protect them from cold nights, because temperatures below about 10°C (50°F) slow their growth and frost will kill them. A layer of mulch around the base helps keep the soil moist and stops weeds.

Flowering and Fruit

Small white flowers appear in summer. After a flower is pollinated, its petals drop off and a tiny green chili starts to grow. Gently shaking indoor plants or brushing the flowers with a soft paintbrush can help them set fruit.

Pests and Diseases

Chili plants are usually healthy, but watch out for these problems:

• Aphids – tiny green insects that cluster on shoot tips and suck the sap. Spray them off with a strong jet of water.
• Caterpillars – such as corn earworms, which chew leaves and bore into fruits. Pick them off by hand.
• Viruses – such as tobacco mosaic virus, which causes mottled yellow leaves and twisted fruit. There is no cure, so remove infected plants. Controlling aphids helps stop viruses spreading.

If you have a bigger problem, your local garden center or extension service can give advice.

Harvesting and Storing

Chilies need sunshine and warmth to ripen fully, which is another reason to sow early. You can pick them green, but they are usually sweeter and hotter when fully colored. Snip them off with scissors or pruners rather than pulling, and harvest outdoor plants before the first frost. Unripe fruit can finish coloring indoors on a sunny windowsill.

Extra chilies can be frozen whole or dried on a string in a warm, airy place, ready for your favorite recipes.

Safety tip: Hot chilies can sting your skin and eyes. Ask an adult to help when cutting them, wear gloves if you can, and always wash your hands afterward before touching your face.

Chilli pepper FAQs

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