The Aji Amarillo, or “yellow chili,” is a distinctive pepper variety of the Capsicum baccatum species, originating from the Andean regions of Peru and Bolivia. This pepper is celebrated for its unique flavor profile, which combines a moderate heat level, typically between 30,000 and 50,000 Scoville Heat Units, with bright, fruity, and slightly sweet notes. The pods mature to an intense golden-orange color, making them a vibrant and signature ingredient in traditional Peruvian cuisine.
Starting Seeds Indoors
The Aji Amarillo requires a significantly longer growing season than many common pepper varieties, making an early indoor start mandatory for most climates. Seeds should be sown approximately ten to twelve weeks before the last expected spring frost date to ensure the plants reach maturity and produce fruit. Sowing the seeds about a quarter of an inch deep in a sterile, fine-textured seed-starting mix prevents “damping off,” a common fungal issue for young seedlings.
Successful germination relies heavily on consistent, high heat. An ideal soil temperature range is between 80°F and 90°F, which almost always requires the use of a seedling heat mat placed beneath the trays. A clear plastic humidity dome placed over the tray will help retain moisture and warmth, creating a miniature greenhouse effect that accelerates sprouting.
Once the first seedlings emerge, the humidity dome must be removed immediately to prevent disease, and the plants should be placed under strong grow lights for at least 14 hours per day. After the seedlings develop their first set of true leaves, they should be carefully transplanted into four-inch pots. This step allows the root system to expand and strengthen, preparing the young plant for the eventual transition to the garden.
Ideal Environmental Conditions and Transplanting
These peppers demand a location that provides full, direct sun exposure for a minimum of six to eight hours daily to support their vigorous growth habit. The planting site must offer well-draining soil, as wet roots are a common cause of plant failure in peppers. A slightly acidic to neutral soil pH, ideally ranging from 6.0 to 7.0, optimizes nutrient uptake for the plants.
The timing of the final move outdoors is determined by temperature. Aji Amarillo plants are highly sensitive to cold and should only be transplanted once nighttime temperatures are consistently above 55°F. Before planting into the garden or large containers, the plants must undergo a “hardening off” period, gradually exposing them to increasing amounts of direct sun and wind over ten to fourteen days.
Once safely relocated, plants should be spaced about eighteen to twenty-four inches apart to allow for adequate air circulation and lateral growth. Aji Amarillo plants can grow quite tall, sometimes reaching six or seven feet, requiring a significant footprint in the garden. Proper spacing helps prevent the spread of fungal diseases and ensures each plant receives sufficient light.
Ongoing Maintenance and Season-Long Cultivation
Throughout the long summer cultivation period, consistent watering is essential. The plants require deep watering whenever the top inch of soil feels dry, but they must never be allowed to sit in soggy conditions, which can lead to root rot. Using a layer of organic mulch around the base of the plant helps to regulate soil temperature and retain moisture, minimizing the stress of hot, dry spells.
Aji Amarillo require a regular application of fertilizer to support their growth and fruiting cycle. Early in the season, a balanced fertilizer high in nitrogen supports the development of strong stems and lush foliage. Once the plants begin to flower, the fertilization regimen should shift to a formula lower in nitrogen but higher in phosphorus and potassium to encourage fruit production.
Because they grow into large, multi-stemmed plants, providing physical support is often necessary, especially once the branches become heavy with fruit. Staking the main stem or surrounding the plant with a sturdy tomato cage prevents the plant from collapsing. Gardeners must remain patient, as the plants will take a significantly longer time to flower and set fruit than quicker varieties like jalapeños.
Harvesting, Ripening, and Utilizing the Pods
The Aji Amarillo often requires 90 to 100 days from the time of transplant before the pods fully ripen. The pods initially develop as green but will gradually transition to a vibrant, deep golden-orange color when they are fully mature. Harvesting too early will result in a less flavorful pepper, so waiting until the color is fully saturated is recommended.
The mature pods are typically four to five inches long and should be removed using sharp scissors or a knife to avoid damaging the branches. Leaving a small piece of the stem attached, known as the calyx, helps to improve the storage life of the peppers. The harvest often extends into late fall, right up until the first hard frost threatens the plant.
Once harvested, the peppers are exceptionally versatile and can be used immediately in their fresh state for sauces and salsas. A common preparation is blending the fresh pods into a paste, which is a base ingredient for many Peruvian dishes. Alternatively, the pods can be frozen whole for later use or sliced and dried to be ground into a flavorful powder.