Zucchini
Cucurbita pepo
Also known asCourgette · Summer squash · Marrow (mature) · Calabacín · Zucchine
Environment
The bounded range this crop tolerates. Strict on light; outside the DLI band, yields drop sharply.
Climate and zones
- USDA zones
- 10–13 (winter low around -1°C)
- Frost
- frost sensitive (dies at first frost)
- Season
- warm (summer, frost-sensitive)
Growing systems
Root mass: heavy. Thin-channel systems can't hold this crop.
Growing media
| Medium | pH effect | 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 | high | high |
Nutrient demand by stage
NPK ratios are relative weights. EC targets shift through the plant's life.
| Stage | N | P | K | EC (mS/cm) |
|---|---|---|---|---|
| seedling | 1 | 1 | 1 | 1 |
| vegetative | 3 | 1 | 2 | 1.9 |
| flowering | 2 | 2 | 3 | 2.1 |
| fruiting | 1 | 2 | 4 | 2.2 |
Companion-growing notes
- Heavy uptake of potassium, calcium. Co-grown crops with the same demand will end up deficient even at "correct" EC.
- Very high transpiration. Reservoir drops fast; expect daily top-ups and EC creep.
Aquaponics suitability
Compatible
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 highly productive hydroponic crop. Large container (20 L) or media bed. EC 2.0-3.0 mS/cm. pH 5.5-6.8. Temperature: 20–30°C. High light (DLI 18-28 mol/m2/day). Plants are large and need space. Hand-pollination required indoors: transfer pollen from male flowers (thin straight stem, no fruit swelling at base) to female flowers (small fruit swelling at the base) using a paintbrush. From transplant to first harvest: 45-55 days (one of the fastest fruit-bearing crops). Harvest every 1-2 days at 15–20 cm; leaving oversized zucchini on the plant slows production. Powdery mildew is the most common disease; resistant varieties and good airflow help. The prolific production makes zucchini one of the best-value hydroponic crops for home growers. The edible flowers are a bonus harvest: pick male flowers in the morning when fully open. For squash blossom preparation: stuff with a mixture of ricotta, mozzarella, and a single anchovy fillet, dip in a light batter, and fry until golden.