Vegetable · Solanaceae
Chili Pepper
Capsicum annuum
Hand it heat, sun, and steady water, and a chili plant will pile on fruit from summer right into fall.
Full sun
Every 2–4 days
59–86°F · 15–30°C
70–85 days
Overview
Chili peppers bring real heat to a garden, and they more than earn their spot. They sit in the nightshade family right next to the tomato, got their start in the Americas, and these days you'll find them growing just about anywhere people garden. Think of it as a warm season annual that's just as happy in a sunny bed as it is in a pot baking on a hot patio.
There's a huge spread in what the fruit can be. Some peppers stay mild and thick-walled, perfect for eating fresh, while others come on so fierce you'll want gloves at the cutting board. The heat itself comes from capsaicin, which packs into the ribs and seeds, and it's the very same stuff that irritates skin, eyes, and the mouths of most animals.
These plants ask for a little patience up front and warmth the whole way through. They're slow off the mark from seed and they really do sulk when it's cold, but hand them full sun, even moisture, and a long warm season and you'll be picking fruit clear up until frost.
Care
The short version: give them full sun and steady warmth, and keep the soil evenly moist so the fruit doesn't rot out at the bottom. Set them in rich, well drained ground, feed a little through the season, and resist the urge to send them out into the cold too soon.
Light
Chilis are after full sun, so aim for eight or more hours a day. Shortchange them on light and you'll end up with leggy, thin-leaved plants and a lot fewer peppers come harvest.
Water
Keep that soil evenly moist, water deeply to at least 6 inches, and mulch to lock the moisture in. Steady watering counts the most during flowering and fruit set, because those dry-then-wet swings are exactly what bring on blossom end rot. If they're in a pot or you're in a heat wave, plan on watering every 2 to 4 days.
Soil
Go with well drained loam or sandy loam that's loaded with organic matter. They like a pH between 6.0 and 6.8, leaning a little acidic, and solid drainage keeps the roots from sitting in soggy ground.
Temperature
Warmth is their thing, and they do best between 59°F and 86°F (15°C to 30°C). Cold soil drags them down early on, and fruit set gets shaky when the days run too hot, so what really fills the plant out is a long, mild stretch.
Humidity
Average humidity somewhere around 40% to 70% does the job, so this isn't a number to lose sleep over. Airflow matters a lot more, since crowded, damp leaves are what invite the bacterial spots that bug peppers.
Feeding
Feed once a month through the growing season with a balanced vegetable fertilizer. Side-dress with calcium nitrate about 3 to 4 weeks after transplanting, then again a few weeks down the line, to help fruit set along, but let a soil test guide you instead of guessing.
Pruning
There's barely any pruning to do here. If you like, pinch off the first flowers for bushier growth and stronger roots, snip away any beat-up or diseased leaves, and stake the taller plants so a heavy fruit load doesn't tip them over.
Repotting
Treat a chili as a one-season plant that you start fresh from seed every year. Bump the seedlings up into bigger pots before they go outside so the roots never get a chance to coil, and keep an eye out for circling roots or fast wilting, both signs a young plant has outgrown its cell.
Size & spacing
Most chili plants reach 12 to 35 inches (30 to 90 cm) tall depending on the type, and spread out to 12 to 24 inches (30 to 60 cm) across. Give each one that much elbow room so air can move and the leaves stay nice and dry.
When to plant
Chili peppers are all about heat and won't put up with frost. Get the seeds started indoors a good while before the last frost, keep the transplants waiting until nights settle above about 55°F (13°C), and you'll be picking fruit from summer into fall.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: 6 to 8 weeks before the last spring frost
- Plant: After the last frost once night temperatures stay above about 55°F (13°C)
- Harvest: Summer to fall harvest of fruit
Hardiness
USDA hardiness zones: 9–11
Temperature: down to -7°C
Troubleshooting
Pretty much all pepper trouble shows up on the fruit, the leaves, or the flowers. Spot those early signs and you can jump in before a small issue runs through the whole plant. Find what matches below, then act while it can still do some good.
Angular brown leaf spots ringed with yellow
That's bacterial leaf spot, and it moves quickly in wet, splashy weather and can leave a plant bare. Once a plant is badly marked there's no fixing it, so just pull and toss the worst ones. From there, water down at the base, keep your hands off the leaves while they're wet, and rotate peppers well away from tomatoes and the rest of their nightshade family.
Fix:
- Remove and discard heavily infected plants
- Avoid overhead watering and handling plants when wet
- Use copper-based products where appropriate
Dark, sunken patch on the bottom of the fruit
What you're looking at is blossom end rot, and the cause is usually watering that's all over the place, not soil that's short on calcium. If the soil keeps going from bone dry to soaked, the plant just can't move calcium up into the fruit while it's forming. So water on a regular schedule, lay down some mulch to keep things even, and don't pile on the nitrogen.
Fix:
- Maintain even soil moisture and mulch to buffer drying
- Avoid over-applying nitrogen fertilizer
- Confirm adequate calcium with a soil test and amend if needed
Flowers drop without setting fruit
When the weather goes to extremes, peppers just let their open blossoms fall, dropping flowers once the days climb past 90°F (32°C) or nights dip below about 60°F (16°C). Don't worry, the plant stays green and healthy through it. Keep the soil evenly moist, back off the nitrogen while it's blooming, and fruit set kicks back in as soon as the weather calms down.
Fix:
- Wait for moderate temperatures, when fruit set usually resumes
- Keep soil evenly moist
- Avoid heavy nitrogen feeding during flowering
Curled leaves with clusters of tiny insects and sticky residue
Those little soft specks, anywhere from green to black, are aphids, and they pile up on shoot tips and the backs of leaves while leaving a sticky honeydew behind. A hard blast from the hose knocks most of them loose, and you only really need insecticidal soap or spinosad when the colonies get out of hand. Want some help? Lady beetles and lacewings will mop up whatever's left.
Fix:
- Dislodge colonies with a strong spray of water
- Apply insecticidal soap or spinosad if populations are high
- Encourage natural predators such as lady beetles and lacewings
Toxicity
The fruit is good to eat and a kitchen staple the world over, so people are perfectly fine around chilis. The catch? Capsaicin, the compound behind the heat, is a strong irritant for cats, dogs, and most animals, and it can leave them with a burning mouth, drooling, and a sour stomach. Birds are the one odd exception and don't mind it in the least.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock
Safe for
People · Birds
Cats Mild
Bite into the fruit and a cat ends up with a mouthful of burn. You'll likely see drooling, pawing at the mouth, and maybe a bit of vomiting or loose stool that clears up on its own.
Dogs Mild
Chew a pepper and a dog feels that same sting, so look for drooling, a queasy stomach, and a sudden urge to drink. Most are fine again once the heat dies down and they've had some water.
Horses Caution
Horses hardly ever go near the spicy fruit, but capsaicin would still burn the mouth and upset the gut, so it's smart to keep the plants somewhere they can't reach.
Rabbits Caution
For a small grazer the heat is rough. One nibble can leave a rabbit drooling and turning away from food, so keep it from browsing the plant at all.
Livestock Caution
Goats, sheep, and cattle aren't fans of the burn and tend to steer clear of peppers, though a nosy one that does eat the fruit can wind up with an irritated mouth and stomach.
Birds Safe
Birds feel none of the heat at all. They simply don't have the receptor capsaicin works on, and that's the whole reason wild peppers get birds to haul off and scatter their seeds.
People Edible
For people, chili fruit is a kitchen staple and safe to eat, hot as it gets. Just glove up when you're cutting the really fiery types and keep that cut flesh away from your eyes.
Capsaicin causes painful skin and eye irritation when handling or cutting hot peppers. Wear gloves, avoid touching your eyes or face, and wash hands thoroughly afterward; inhaling fumes from cut peppers can irritate the airways.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
United Kingdom
Animal PoisonLine: 01202 509000 (fee applies)
Australia
Animal Poisons Helpline: 1300 869 738
Varieties
There are thousands of chili varieties out there, but only a handful keep turning up in home gardens. These are the ones worth knowing both by name and by how much heat they bring.
Jalapeno
A thick-walled, medium-hot pepper you'll usually pick while it's still green, and the one most folks reach for when fresh eating and pickling.
Cayenne
Long, thin, and wrinkled, it brings more heat than a jalapeno and dries down into the ground cayenne powder you already know.
Habanero
Shaped like a little lantern and seriously hot, this one belongs to the Capsicum chinense species and hides a distinct fruity aroma beneath all that heat.
Thai (bird) pepper
Small and fiercely pungent, the fruit points upward in clusters on tidy, compact plants.
How to propagate
Chili peppers come up from seed, and honestly the only catch is giving them enough warmth and a long enough running start indoors.
SeedModerate
Start seed indoors 6 to 8 weeks before the last spring frost · Germinates in roughly 1 to 3 weeks in warm soil (about 80-85°F); transplants are field-ready 6 to 8 weeks after sowing
You'll start peppers from seed, and the one thing they really insist on is steady warmth to get moving. Get them going indoors 6 to 8 weeks before your last frost, set them over bottom heat near 80°F to 85°F (27°C to 29°C) with plenty of bright light, and they'll sprout in about 1 to 3 weeks. Give it another 6 to 8 weeks and the seedlings are good to head outside, as long as you've hardened them off and the frost is behind you.
Myths
Chili peppers are deadly poisonous to dogs and cats.
Capsaicin stings, sure, but it doesn't poison the way a real toxin would. Chew a hot pepper and a pet ends up with a sore mouth and a queasy stomach for a bit, and that's the end of it, no lasting damage. On top of that, culinary peppers aren't on the ASPCA's classic toxic-plant list.
The heat in chili peppers harms birds.
Birds don't even notice capsaicin and tuck into the fruit without so much as a flinch. That blind spot is the whole point, because wild peppers count on birds to swallow the fruit and carry the seeds far and wide.