Snap peas
Pisum sativum var. macrocarpon
Also known as: Sugar snap peas, Sugar peas, Snap peas (American), Mangetout (UK, broader term)
Quick facts
- Category
- fruiting
- Difficulty
- beginner
- Days to harvest
- 60 to 80 days
- Harvest type
- continuous production over weeks or months
- Spacing
- 10 cm between plants
Environment
- Temperature
- 7–24°C
- pH
- 6 to 7
- EC (hydroponic)
- 1.4 to 2.2 mS/cm
- Daily light
- 16 to 22 mol/m²/day (strict, will fail outside this range)
Climate and zones
- USDA zones
- 3 to 9 (winter low around -40°C or warmer)
- Frost tolerance
- tolerates light frost
- Season
- cool (spring and fall crops)
Viable growing environments:
- outdoor year-round (in zone)
- 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
Snap peas works in:
- media bed (ebb and flow)
- wicking bed
- soil bed
- drip / Dutch buckets
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 (snap peas 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 |
| 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 | 1 | 1 | 1 | 0.8 |
| vegetative | 2 | 1 | 2 | 1.6 |
| flowering | 1 | 2 | 3 | 1.9 |
| fruiting | 1 | 2 | 4 | 2 |
Companion-growing notes
- Heavy uptake of potassium. Co-grown crops with the same demand will end up deficient even at "correct" EC. Plan around this in shared reservoirs.
- High transpiration. Reservoir level will need regular top-ups during fruiting or flowering.
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 cool-season vine crop for hydroponic systems with trellis support. EC 1.5-2.5 mS/cm. pH 6.0-7.0. Temperature: 10–22°C (cool-season; heat above 25°C reduces quality and causes pods to become tough and starchy). Moderate light (DLI 14-20 mol/m2/day). Climbing varieties need 1.5–2 m of trellis; bush varieties ('Sugar Ann') stay under 60 cm. From seed to first harvest: 55-70 days. Harvest when pods are plump, round in cross-section, and the peas inside are visible through the pod wall. The pod should snap cleanly when bent. Daily harvesting keeps the vine producing. Each plant produces 100–200 g of pods over a 3-4 week harvest period. Eat immediately after picking for the best sweetness (sugars convert to starch within hours). Raw snap peas are one of the best snacking vegetables: sweet, crunchy, and satisfying.
Verified against: rhs-uk. Last reviewed 2026-05-15.