Peppers
Heat-loving, semi-permanent residents. Peppers occupy hydroponic positions for months — they’re not rotation crops. They thrive in exactly the conditions that kill lettuce.
Optimal Conditions
| Parameter | Range | Notes |
|---|---|---|
| Day temperature | 75-85°F | Can tolerate 90°F+, but fruit set drops above 90°F |
| Night temperature | 65-70°F | Fruit set requires warm nights |
| VPD | 0.8-1.2 kPa | Moderate transpiration needs |
| DLI | 15-25 mol/m²/d | More light = more fruit. Above 30 mol is diminishing returns |
| pH (hydro) | 5.8-6.3 | Slightly less acidic than lettuce |
| EC | 2.0-3.5 mS/cm | Heavy feeder during fruiting |
| Photoperiod | 14-18 hours | Day-neutral but benefits from long days |
Varieties for This Greenhouse
| Variety | Type | Days to Fruit | Heat | Scoville | Notes |
|---|---|---|---|---|---|
| Shishito | Sweet/mild | 60-80 | Excellent | 50-200 | Primary pick. 1/10 pods are spicy. |
| Jalapeño | Hot | 70-80 | Excellent | 2,500-8,000 | Classic, reliable |
| Mini Sweet | Sweet | 55-65 | Good | 0 | Snacking peppers, compact plants |
| Habanero | Hot | 90-120 | Excellent | 100,000+ | Needs the south zone heat |
| Banana | Sweet/mild | 65-75 | Good | 0-500 | Good for pickling |
Recommendation: Shishito as the primary pepper. Compact, prolific, and the east zone’s temperature profile (91°F peak) is within their sweet spot. Reserve 4-6 hydro positions as semi-permanent.
Zone Recommendation
Primary: East Zone hydroponic (for most varieties) Alternative: South Zone shelving (for heat-lovers like habanero)
| Zone | Peak Temp | Fit |
|---|---|---|
| East (hydro) | ~91°F | ✅ Ideal for shishito, jalapeño, mini sweet |
| South (shelving) | ~100°F+ | ✅ For habanero, superhots that want maximum heat |
| West | ~mid-range | ✅ Viable for all varieties |
Peppers tolerate the greenhouse’s hottest days. Even the south zone’s 100°F+ peaks don’t damage established pepper plants — fruit set just slows above 90°F. The east zone’s more moderate temperatures (75-91°F range) optimize for both plant health AND fruit production.
Hydroponic Growing Notes
- Semi-permanent: Pepper plants occupy positions for 3-6 months. Plan positions accordingly.
- Support: Plants get 18-24” tall. Net cups may need stakes or ties.
- Nutrient transition: Start at EC 1.5-2.0 during vegetative growth. Increase to 2.5-3.5 during flowering/fruiting.
- Pruning: Remove first flowers to encourage branching. Top at 12” for bushier growth.
- Harvest: Pick when color turns. Frequent picking encourages more production.
Longmont-Specific Notes
- Growing season advantage: The greenhouse extends peppers from Longmont’s outdoor 90-day frost-free window to year-round production.
- Light is adequate: At 17-27 mol/m²/d estimated actual DLI, the greenhouse exceeds pepper minimum (15 mol) and hits optimal range (20-25 mol) on clear days.
- Pollination: Peppers are self-pollinating but benefit from vibration. The exhaust fans provide air movement; occasional gentle shaking helps.
→ See All Crop Profiles → See South Zone for the heat-loving zone profile