How to grow Chilli Pepper (Jalapeno)

Capsicum annuum

🥕 Vegetable 🌱 Grown each year

Jalapeño, pronounced 'halapeno', is a popular green bullet-shaped chilli pepper, 5-9cm long by 2.5cm wide, originating from Xalapa, Mexico. It's known for its medium heat (2,500-10,000 SHU) and is one of the easiest chillies to grow, producing abundant, quality pods. Plants grow 75-90cm tall and continuously set fruit from August onwards. While typically harvested green, they ripen to red and can be smoked to make 'chipotle'. Jalapeños are versatile, widely used on nachos, in 'hot pepper' eating contests, and are excellent for pickling.

At a glance: Sow late April to late May, harvest from mid July.

When to sow, plant and harvest

JanFebMarAprMayJunJulAugSepOctNovDec

Sow outdoors

Flowers

Harvest

Timed for a typical UK garden (last frost mid-April). The app uses your own town's frost dates.

Growing Chilli Pepper (Jalapeno): what it needs

Light: Full sun · 6+ hours a day
Watering: Regularly
Soil: Rich, well-draining loam · pH 6.0–6.8
Spacing: 45-60cm apart
In pots: Grows well in containers
Feeding: Feed with a balanced liquid fertilizer every 2-3 weeks once flowers appear.
Harvest: About 70 days from sowing
Hardiness: USDA zones 9–11
Difficulty: Easy

Step by step

Late April – late May · 2 weeks after the last spring frost
Sow Seeds Outdoors (Warm Climates/Greenhouse) (optional)
Direct sow only in very warm climates or a heated greenhouse after all frost risk has passed. Not recommended for temperate zones due to long growing season.
7–14 days after “Sow Seeds Indoors” · Early May – mid May
Check Germination
Seedlings should emerge in 7-14 days. Ensure consistent warmth and moisture. Thin to one strong seedling per cell.
21 days after “Transplant Outdoors” · Late May
Add Plant Support
Stake or cage plants as they grow to support the fruit load and prevent stems from breaking.
21 days after “Add Plant Support” · Mid June
Start Feeding
Begin feeding with a balanced liquid fertilizer (e.g., tomato feed) once the first flowers appear to encourage fruit set.
30–90 days after “Start Feeding” · Mid July – mid September
Harvest Jalapeno Chillies
Pick fruits when they are firm, glossy, and green (5-9cm long). Harvesting regularly encourages more production. Fruits can also be left to ripen to red for a sweeter, hotter flavour.