Pimiento
Capsicum annuum
Also known as: Pimento, Cherry pepper (when round), Sweet red pepper, Spanish pimiento
Quick facts
- Category
- fruiting
- Difficulty
- beginner
- Days to harvest
- 75 to 90 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
- 20 to 28 mol/m²/day (strict, will fail outside this range)
Climate and zones
- USDA zones
- 4 to 12 (winter low around -34°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
Pimiento 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 (pimiento 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 compact, productive sweet pepper for hydroponic systems. EC 2.0-2.8 mS/cm. pH 5.8-6.5. Temperature: 20–28°C. Moderate to high light (DLI 16-22 mol/m2/day). Plants are compact (30–50 cm) and produce well in DWC, NFT, or drip systems. From transplant to red-ripe harvest: 75-90 days. Each plant produces 15-25 peppers. Harvest when fully red and sweet. The thick walls roast and peel beautifully. For pimiento cheese (the Southern classic): dice roasted and peeled pimientos, mix with sharp cheddar (shredded), mayonnaise, a pinch of cayenne, and salt. The homemade version using fresh-roasted pimientos is noticeably better than versions made with jarred peppers. For stuffing olives: dice pimiento into small strips and push into pitted green olives. Calcium supplementation prevents blossom end rot. The compact plant size and prolific production make pimiento a practical hydroponic pepper for growers who eat Southern food or enjoy Mediterranean appetizers.
Verified against: rhs-uk, u-of-georgia-extension, rutgers-cooperative-extension. Last reviewed 2026-05-15.