General
Chili peppers (Capsicum spp.) include sweet to very hot varieties. C. annuum typically matures fastest and suits cooler summers; C. chinense (e.g., habanero) and some C. baccatum need a longer, warmer season. In Scandinavia they are best precultivated indoors and grown in greenhouse or a warm, sheltered patio. Plants are technically short-lived perennials but are usually grown as annuals. Night temperatures below 12–14°C and any frost will stall growth and damage plants.
Light
Full sun; 6–10 hours of direct light daily. Indoors, use strong grow lights.
Soil type
Well-drained, fertile, humus-rich loam or high-quality potting mix with added compost and perlite. Avoid heavy, waterlogged soils.
Water requirement
Moderate and consistent. Keep evenly moist but never soggy; allow the top layer to dry slightly between waterings.
Nutrient requirement
Medium to high. Start with balanced nutrients, then shift to high-potassium feed during flowering and fruiting.
Precultivation
Sow 8–12 weeks before the last frost (January–March for Sweden). Use a sterile seed mix; sow 0.5–1 cm deep. Ideal germination temperature is 24–28°C with steady moisture and high humidity; a heat mat speeds germination. Provide strong light immediately after emergence to prevent legginess (PPFD ~200–400 µmol/m²/s). Pot on as roots fill cells. Maintain 18–22°C days, 16–18°C nights. Hot C. chinense often needs the earliest sowing and more warmth. Direct sowing outdoors is generally not recommended in Nordic climates.
Planting
Harden off 7–10 days before transplanting. Plant when nights reliably stay above ~12°C (often late May–June) or keep under cover. Spacing: 35–45 cm between plants, 45–60 cm between rows; in pots use 7–12 L for compact/medium plants, 15–25 L for large varieties. Use stakes or a small cage for support. Mulch to stabilize soil moisture. In greenhouses, ensure good ventilation.
Pruning
Pinch the growing tip of very lanky or early-sown plants to encourage branching. Remove weak interior shoots and the lowest leaves as the plant grows to improve airflow. For compact varieties minimal pruning is needed; for tall types, thin crowded side shoots and tie to stakes. Optional: remove the very first ‘crown’ flower to encourage vegetative growth early in the season.
Maintenance
Water deeply but infrequently; aim for even moisture to prevent blossom end rot and fruit cracking. Feed little-and-often: start with a balanced organic fertilizer after transplanting, then switch to a tomato/chili feed higher in K from first buds onward. Supplement with seaweed extract or compost tea every 2–3 weeks. Maintain good airflow; shake plants lightly or use an oscillating fan to aid pollination. Scout weekly for pests. In containers, flush with clear water monthly to avoid salt buildup.
Harvest
Harvest when fruits reach full size and desired color (green to red/orange/yellow depending on variety). Use scissors to avoid tearing stems. Regular picking promotes more fruiting. Store fresh chilies at 10–12°C with moderate humidity; for long-term, air-dry, dehydrate, ferment into hot sauce, or freeze chopped fruits.
Common issues
Pests: aphids, spider mites, whitefly, and thrips—use sticky traps, insecticidal soap, and encourage beneficials. Diseases: Botrytis and powdery mildew in humid, stagnant air—prune for airflow and ventilate. Physiological: blossom end rot (uneven moisture or Ca imbalance), flower drop from temperature stress (<12–14°C nights or >32–34°C days), and sunscald on suddenly exposed fruits—keep moisture even, feed moderately, and avoid abrupt defoliation.
Rotation schedule
Rotate with a 3–4 year break from all Solanaceae (tomato, potato, eggplant). Follow heavy feeders with legumes or well-composted beds. In containers, refresh at least 1/3–1/2 of the potting mix annually or replace entirely to reduce disease carryover.
Pollination
Self-pollinating flowers; gentle shaking or airflow improves fruit set, especially in greenhouses or indoors.
Companion plants
Basil, marigold, onions, scallions, nasturtium, leafy greens. Herbs that attract pollinators/beneficials (e.g., dill, coriander) are helpful nearby.
Incompatible plants
Fennel; avoid close proximity to potatoes and other Solanaceae with disease issues. Do not plant after tomatoes, eggplants, or potatoes in the same soil within 3–4 years.
