Korean chile
Capsicum annuum
Also known as: Gochu, Korean red pepper, Gochugaru pepper (dried form), Cheongyang chile (a hotter cultivar)
Quick facts
- Category
- fruiting
- Difficulty
- beginner
- Days to harvest
- 80 to 100 days
- Harvest type
- continuous production over weeks or months
- Spacing
- 50 cm between plants
Environment
- Temperature
- 18–30°C
- pH
- 6 to 6.8
- EC (hydroponic)
- 1.8 to 2.6 mS/cm
- Daily light
- 22 to 30 mol/m²/day (strict, will fail outside this range)
Climate and zones
- USDA zones
- 5 to 12 (winter low around -29°C or warmer)
- Frost tolerance
- frost sensitive (dies at first frost)
- Season
- warm (summer crops, frost-sensitive)
Viable growing environments:
- outdoor in growing season (annual)
- unheated greenhouse / hoop house
- heated greenhouse
- indoor (heated home)
- indoor hydroponics under grow lights
USDA zone bounds reflect outdoor year-round survival. Anywhere outside the bounded zone range, this crop still grows as an annual in the warm months (outdoor_seasonal), under cover (greenhouse), or indoors under lights.
Growing systems
Korean chile works in:
- drip / Dutch buckets
- media bed (ebb and flow)
- soil bed
Growing media
The substrate the roots sit in. Choice depends on the system (clay pebbles don't fit NFT channels; rockwool isn't used in media beds) and the crop (korean chile works in the media listed below).
| Medium | pH effect | Water retention | Bacterial surface |
|---|---|---|---|
| Expanded clay pebbles (LECA) | neutral / inert | low | high |
| Coco coir (Coconut coir) | slightly acidic | high | moderate |
| Perlite (Expanded volcanic glass) | neutral / inert | very low | low |
| Rockwool (Mineral wool) | alkaline until pre-soaked | very high | low |
| Soil-based mix (Potting soil) | varies by source | high | high |
Bacterial surface area matters for aquaponics: clay pebbles, lava rock, and pumice double as biofilter substrate. Low-surface media (rockwool, perlite, pea gravel) work in hydroponics but need a separate biofilter in aquaponics.
Nutrient demand by stage
NPK ratios are relative weights at each growth stage; the nutrient mix calculator scales them to absolute grams or ml. EC targets shift through the plant's life: seedlings need a much lighter solution than fruiting adults.
| Stage | N | P | K | EC target (mS/cm) |
|---|---|---|---|---|
| seedling | 2 | 1 | 1 | 1.2 |
| vegetative | 3 | 1 | 2 | 1.8 |
| flowering | 1 | 2 | 3 | 2.2 |
| fruiting | 1 | 2 | 3 | 2.4 |
Companion-growing notes
- Heavy uptake of potassium, calcium. Co-grown crops with the same demand will end up deficient even at "correct" EC. Plan around this in shared reservoirs.
Aquaponics suitability
Compatible with typical aquaponics nutrient profiles. Fish waste provides enough nitrogen for healthy growth; supplemental potassium, calcium, and iron may still be needed depending on fish stocking density.
Care notes
A productive hydroponic pepper for Korean cooking enthusiasts. EC 2.0-3.0 mS/cm. pH 5.8-6.5. Temperature: 20–30°C. High light (DLI 18-25 mol/m2/day). Plants are medium-sized (50–80 cm). From transplant to red-ripe fruit: 85-100 days (must be fully red before drying for gochugaru). Each plant produces 20-35 peppers. For gochugaru production: harvest fully red peppers, remove stems and seeds, dry in a dehydrator at 55–60°C until leathery but not brittle, then grind coarsely in a food processor (not a fine powder; gochugaru should have a coarse, flaky texture). The resulting product should be vibrant red, slightly oily, and sweet-smelling. Use for kimchi, gochujang, tteokbokki, and any Korean recipe calling for gochugaru. Homemade gochugaru from freshly dried peppers is dramatically more flavorful than the stale, often years-old product available at many Korean grocery stores. Seeds are available from Korean seed suppliers and some specialty US seed companies.
Plan a setup with Korean chile
Verified against: rural-development-administration-korea, seoul-national-u, rhs-uk. Last reviewed 2026-05-15.