Aji amarillo

Quick facts

Category

fruiting

Difficulty

intermediate

Days to harvest

100 to 130 days

Harvest type

continuous production over weeks or months

Spacing

75 cm between plants

Environment

Temperature

18–30°C

pH

5.8 to 6.8

EC (hydroponic)

1.8 to 2.6 mS/cm

Daily light

22 to 32 mol/m²/day (strict, will fail outside this range)

Climate and zones

USDA zones

9 to 13 (winter low around -7°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

Aji amarillo 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 (aji amarillo works in the media listed below).

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.

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

Grows well in hydroponic systems with warm temperatures and long seasons. EC 2.0-3.0 mS/cm. pH 5.5-6.5. Temperature: 21–30°C (the Capsicum baccatum species group prefers warmer conditions than C. annuum varieties). Full sun or strong supplemental light (DLI 20-30 mol/m2/day). The plants are large and benefit from staking or cage support. Fruiting takes 90-120 days from transplant, longer than most C. annuum peppers. Calcium supplementation prevents blossom end rot on developing fruit. Increase potassium during fruiting for better flavor and heat development. Harvest when fruits turn fully orange. The plants are perennial in frost-free conditions and can produce for multiple years in a hydroponic greenhouse. Aphids and whiteflies are the most common pests. The long season and large plant size make aji amarillo more practical for greenhouse hydroponics than countertop systems. Surplus fruit can be made into paste (aji amarillo paste), frozen, or dried for year-round use. In traditional Peruvian cooking, aji amarillo paste is a foundation ingredient comparable to tomato paste in Italian cuisine. Growing your own provides access to a product that's expensive and inconsistent in quality when imported. The fresh peppers also freeze well: blanch briefly, peel if desired, and store in freezer bags. Each plant produces 30-50 peppers over a season under good hydroponic conditions.

Further reading

• Getting started with hydroponics: which system to build first
• Understanding nutrient solutions: N-P-K, micronutrients, and why your lettuce turned yellow