Jalapeño pepper

Sun

Full sun, ideally at least 6-8 hours daily; light afternoon shade can help in very hot climates.

Water

Water thoroughly when the soil surface starts to dry. Keep moisture even during flowering and fruiting without leaving roots waterlogged.

Soil

Fertile, well-drained soil enriched with compost, ideally pH 6.0-7.0. Use quality potting mix in containers with drainage holes.

Height

2-3 ft (0.6-0.9 m)

Spread

1-2 ft (0.3-0.6 m)

Flowers

Small white flowers from late spring through summer, sometimes continuing into autumn in warm conditions.

Foliage

Smooth, pointed, oval green leaves on branching, increasingly woody stems.

Growth

Moderate to fast in warm weather.

Care needed

Medium

• Pollinators
• Heat tolerant
• Low allergen
• Edible

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Moderate

Toughness

Needs looking after

Pick your zone, country, light and whether you have pets.

1. Planting day

   0.5 ft (0.15 m)

2. After 1 year

   2.5 ft (0.75 m)

   full size

Full size in one season.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Mildly toxic: may upset a stomach

Native to

the US

Growth rate

Fast

• Plant out after frost risk has passed, when nights remain above about 12°C (54°F), spacing plants 18-24 in (45-60 cm) apart.
• Use a container of at least 3-5 US gallons (11-19 litres) for each plant.
• Water at soil level and mulch once the soil is warm to reduce drying and soil splash.
• Apply a balanced vegetable fertiliser as directed; avoid excessive nitrogen, which encourages leaves at the expense of fruit.
• Support heavily laden branches with a short stake and soft ties.
• Cut fruits off with scissors rather than pulling them; wear gloves when cutting hot peppers.

Pruning. Routine pruning is unnecessary. Remove damaged or diseased growth as it appears, and avoid heavy pruning that delays cropping or exposes fruit to sunscald.

Pick firm, glossy, dark-green peppers about 5–9 cm (2–3½ in) long, usually 70–90 days after transplanting, from summer into autumn. Green jalapeños are ready to use; leave some on the plant until fully red for a sweeter, fully ripe pepper. Snip the stalk with scissors or secateurs rather than pulling, and harvest regularly until frost or cold weather ends production.

Late winter

Sow indoors 8-10 weeks before your expected planting-out date; provide bright light and a germination temperature of about 24-29°C (75-84°F).

Spring

Pot seedlings on when roots fill their containers, keeping them warm and brightly lit.

Late spring

Harden plants off gradually and plant outside once frost risk has passed and nights are warm.

Summer

Water consistently, feed as directed and check leaf undersides for pests.

Summer to early autumn

Harvest firm, full-sized green peppers regularly, or leave some to ripen red.

Autumn

Pick remaining usable fruit before frost and remove spent plants; do not compost diseased material.

• Plant in orderly vegetable beds with basil and leafy crops for a compact edible display.
• Grow in large patio pots where the green and red fruits can be seen and harvested easily.
• Use as a productive edging in sunny potagers, allowing room to reach each plant.
• Combine with low marigolds or calendulas for flower colour beneath the upright pepper plants.

Garden styles it suits: Potager (kitchen garden), Edible landscape, Homestead, Small-space, Modern courtyard and Mexican hacienda.

Plant it with: Basil, Lettuce, Spring onions, French marigolds and Calendula.

Wildlife: Flowers are self-fertile but are also visited by bees. Birds can eat ripe peppers without experiencing the burning sensation that mammals do.

• Aphids: check young shoots and leaf undersides; wash off small colonies or use insecticidal soap labelled for edible crops.
• Red spider mites: common in hot, dry greenhouses; inspect for stippled leaves and fine webbing, and use suitable biological controls or a labelled treatment.
• Blossom-end rot: dark, sunken patches at the fruit tip usually follow uneven moisture and disrupted calcium uptake; maintain steady watering rather than adding calcium without a soil test.
• Poor fruit set: cold nights or excessive heat can cause flower drop; provide warmth in cool regions and ventilation or light afternoon shade during extreme heat.

The fruits are edible for people, but capsaicin can strongly irritate the mouth, eyes and skin and may cause stomach upset. Jalapeño is not generally classed as poisonous to cats, dogs or horses, but hot fruit can cause irritation and digestive upset, so do not feed it to them. Leaves and stems are not culinary parts and should not be fed to pets or livestock.

• Serrano pepper (Capsicum annuum (Serrano types))

  Fruits are usually narrower, more slender and hotter than jalapeños, which have broader shoulders and thicker walls.

• Fresno pepper (Capsicum annuum (Fresno types))

  Fruits generally taper to a sharper point and have thinner walls; jalapeños usually have a blunter tip. Shape varies, so a plant label is the best guide.

• Padrón pepper (Capsicum annuum (Padrón types))

  Fruits are typically more wrinkled, irregular and thin-walled than the smooth, thick-walled jalapeño.

Jalapeño means 'from Xalapa', the city in Veracruz, Mexico, associated with this pepper.

Propagation. Sow seed indoors with warmth. Seed saved from open-pollinated plants may come true if protected from crossing with other Capsicum annuum peppers; seed from hybrids may produce variable offspring.

Accepted botanical name

Capsicum annuum

In the US and Canada

Native in the lower 48 states. Introduced in Hawaii, the lower 48 states, Navassa Island, Pacific Basin, Puerto Rico and US Virgin Islands.

Native range

Guatemala, Mexico Central, Mexico Gulf, Mexico Northeast, Mexico Northwest, Mexico Southeast, Mexico Southwest, Bahamas, Belize, Bolivia, Brazil North and Brazil Northeast.

Measured

Average height 60 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.