Vegetable · Solanaceae
Chili Pepper
Capsicum annuum
Hand it heat, sun, and steady water, and a chili plant piles on fruit from summer right through fall.
Full sun
Every 2–4 days
59–86°F · 15–30°C
70–85 days
Overview
Chili peppers turn up the heat in the garden, and they make you work a little for it. They sit in the nightshade family right beside the tomato, traveled out of the Americas, and now thrive wherever people put a spade in the ground. Grow it as a warm season annual and it performs every bit as happily in a sunny bed as it does in a pot baking on a hot patio.
Expect a huge spread of fruit. Some peppers stay gentle and thick-walled and slice straight into a salad, while others crank up hot enough that you'll want gloves at the cutting board. The fire comes from capsaicin, packed into the ribs and seeds, and it's the very same compound that bites at skin, eyes, and the mouths of most animals.
Peppers reward patience up front and warmth all the way through. They take their time germinating and they sulk the moment it turns cold, but hand them full sun, even moisture, and a long warm season and they keep pushing out fruit right up until frost.
Care
The short version: give them full sun and steady warmth, and hold the soil evenly moist so the fruit doesn't rot at the tip. Set them into rich, well drained ground, feed lightly across the season, and never hurry them out into the cold.
Light
Chilis chase full sun, eight or more hours of it every day. Cut their light short and you'll grow leggy, thin-leaved plants that hand back far fewer peppers across the season.
Water
Hold the soil evenly moist, soaking it deeply to at least 6 inches and topping it with mulch to lock that moisture in. That steady rhythm counts the most through flowering and fruit set, because the dry-then-wet swings are exactly what set off blossom end rot. Growing in a pot or riding out a heat wave, plan on watering every 2 to 4 days.
Soil
Set them into well drained loam or sandy loam packed with organic matter. They settle in nicely at a pH between 6.0 and 6.8, leaning a little acidic, and sharp drainage keeps the roots from sitting in wet ground.
Temperature
Warmth is what they live for, with the sweet spot running between 59°F and 86°F (15°C to 30°C). Cold soil drags them back early, and fruit set falters once the days climb too hot, so a long mild run is what packs the plant with fruit.
Humidity
Average humidity somewhere around 40% to 70% does the job, so it's not a number to lose sleep over. Airflow is the bigger lever, since crowded, damp leaves roll out the welcome mat for the bacterial spots that plague peppers.
Feeding
Feed every month through the growing season using a balanced vegetable fertilizer. Slip in a side-dressing of calcium nitrate about 3 to 4 weeks past transplanting, then again a couple of weeks after, to back up fruit set, and trust a soil test over a hunch.
Pruning
Peppers ask for very little pruning. Go ahead and pinch off the first flowers to drive bushier growth and stronger roots, strip away any battered or diseased leaves, and stake the tall ones so a heavy haul of fruit doesn't tip them over.
Repotting
Run the chili as a one-season crop, sown fresh from seed every year. Bump the seedlings up into bigger pots before they head outdoors so the roots never start to coil, and treat circling roots or fast wilting as the tell that a young plant has outgrown its cell.
Size & spacing
Most chili plants reach 12 to 35 inches (30 to 90 cm) tall, the exact height riding on the type, and bush out to 12 to 24 inches (30 to 60 cm) across. Hand each one that much elbow room so air slips through freely and the leaves dry off fast.
When to plant
Chili peppers chase the heat and have no patience for frost. Get the seeds going indoors well ahead of the last frost, keep the transplants back until nights hold above about 55°F (13°C), then start picking fruit from summer on 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
Pepper trouble almost always 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. Pin down what you're seeing below, then act while it can still turn things around.
Angular brown blotches edged in yellow across the leaves
Wet, splashy weather lets bacterial leaf spot race through a plant and can strip it bare. Once a plant is heavily marked there's no turning it around, so pull and toss the worst offenders. From there, water down at the base, leave wet foliage alone, and shift your peppers clear of tomatoes and the rest of the nightshade clan.
Fix:
- Remove and discard heavily infected plants
- Avoid overhead watering and handling plants when wet
- Use copper-based products where appropriate
Sunken dark spot forming at the tip of a pepper
Point the finger at watering, not at calcium-poor soil: this is blossom end rot. Let the ground bounce between bone dry and waterlogged and the plant simply can't move calcium up into the fruit that's filling. Get on a steady watering rhythm, lay down mulch to even out the moisture, and keep the nitrogen light.
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
Blossoms falling off before any fruit forms
When the weather swings to extremes, peppers respond by letting their open blossoms go. Push the days past 90°F (32°C) or drop the nights below about 60°F (16°C) and the flowers drop, even though the plant stays green and perfectly healthy. Keep the soil evenly moist, hold back on nitrogen while it blooms, and watch fruit set kick in again once the temperatures even out.
Fix:
- Wait for moderate temperatures, when fruit set usually resumes
- Keep soil evenly moist
- Avoid heavy nitrogen feeding during flowering
Distorted foliage swarming with little bugs and a sticky film
Look closely and those tiny soft green-to-black dots packing the shoot tips and leaf undersides are aphids, and the sticky honeydew is their calling card. Blast them off with a sharp burst from the hose first. Save insecticidal soap or spinosad for heavy outbreaks, and let lady beetles and lacewings 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
Chili fruit is good eating and a kitchen staple the world over, so people have nothing to worry about. The snag is capsaicin, the compound behind the heat, which acts as a strong irritant on cats, dogs, and most animals and can leave them with a burning mouth, drooling, and a churning stomach. Birds are the strange exception and shrug it off entirely.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock
Safe for
People · Birds
Cats Mild
One bite into the fruit and a cat ends up with a mouthful of burn. Look for drooling, pawing at the mouth, and possibly a bout of vomiting or loose stool that clears up on its own.
Dogs Mild
Chew a pepper and a dog gets the same sting, often with drooling, a queasy stomach, and a sudden urge to drink. Most come right once the heat dies down and they've lapped up some water.
Horses Caution
A horse will usually steer clear of the spicy fruit, yet capsaicin would still scorch the mouth and unsettle the gut, so site the plants somewhere out of reach.
Rabbits Caution
That heat hits a small grazer hard. Even a nibble can set a rabbit drooling and put it off its food, so keep it from browsing the plant at all.
Livestock Caution
Goats, sheep, and cattle tend to find the burn unappealing and walk on past the peppers, though a nosy animal that takes a bite can wind up with an irritated mouth and stomach.
Birds Safe
The heat simply doesn't register for birds. They have none of the receptor capsaicin works on, and that quirk is precisely how wild peppers get birds to ferry off and spread their seeds.
People Edible
Hot as it gets, chili fruit is a kitchen mainstay and good to eat. Pull on gloves before cutting the fiercest sorts and steer the sliced flesh well clear of 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
Chili varieties number in the thousands, yet a handful keep turning up in home gardens. These are the ones worth knowing by name and by their heat.
Jalapeno
Thick-walled and medium-hot, picked most often while it's still green, and the first pick for fresh eating and pickling.
Cayenne
Long, slim, and wrinkled, packing more heat than a jalapeno and drying down into the ground cayenne powder you already know.
Habanero
Shaped like a little lantern and very hot, a member of the Capsicum chinense species, with a clear fruity aroma sitting under the burn.
Thai (bird) pepper
Tiny and fiercely pungent, the fruit points skyward in tight clusters on trim, compact plants.
How to propagate
Chili peppers start from seed, and the whole game is handing them plenty of 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
Raise peppers from seed and the one thing they truly want is steady warmth to get moving. Start them indoors 6 to 8 weeks before your last frost, hand them bottom heat near 80°F to 85°F (27°C to 29°C) plus bright light, and they push up in about 1 to 3 weeks. Give it another 6 to 8 weeks of growing on, harden the seedlings off, and once frost is behind you they're set for the garden.
Myths
Chili peppers are deadly poisonous to dogs and cats.
Capsaicin stings, yet 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 stretch, nothing lasting, and culinary peppers aren't on the ASPCA's classic toxic-plant list.
The heat in chili peppers harms birds.
Capsaicin doesn't even register for birds, so they tuck into the fruit without a flinch. That blind spot is the whole point, because wild peppers count on birds to gulp the fruit down and fling the seeds far and wide.