Batavian lettuce
Lactuca sativa (Batavian / summercrisp type)
Also known asSummer crisp lettuce · Batavia · French crisp · Crisp lettuce
Environment
The bounded range this crop tolerates.
Climate and zones
- USDA zones
- 4–10 (winter low around -34°C)
- Frost
- tolerates light frost
- Season
- cool (spring/fall)
Growing systems
Root mass: light.
Growing media
| Medium | pH effect | Retention | Bacterial surface |
|---|---|---|---|
| Rockwool (Mineral wool) | alkaline until pre-soaked | very high | low |
| Expanded clay pebbles (LECA) | neutral / inert | low | high |
| Coco coir (Coconut coir) | slightly acidic | high | moderate |
| Net pot, no medium (Bare-root) | - | - | - |
| 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 | 0.6 |
| vegetative | 3 | 1 | 2 | 1.2 |
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
An excellent hydroponic lettuce that pairs crisphead texture with the speed and ease of loose-leaf types. Hold EC around 0.8-1.4 mS/cm, since lettuce is a light feeder, and pH 5.5-6.5. The optimum is about 15–22°C, and Batavian types take 24–26°C better than crisphead or butterhead before bolting, though all lettuce bolts as temperatures climb toward 30°C. Keep light moderate, 12-17 mol/m2/day. Heads are ready in five to seven weeks from transplant, or three to four as baby leaf, in NFT, deep water culture, raft and vertical systems. The open head structure gives good airflow to the inner leaves, so tipburn (marginal calcium deficiency) is less of a problem than in butterhead. Outer leaves can be picked progressively while the centre keeps growing. Red-tinged varieties add colour and fetch premium prices. Sow every two to three weeks for a steady supply.
Notable varieties
| Cultivar | Type | Days | Notes |
|---|---|---|---|
| Nevada | open pollinated | 55 | The benchmark heat-tolerant Batavian. Green ruffled heads with thick crisp ribs, holds without bolting through summer in zones 6 and below. The variety US market growers reach for when butterhead season ends in June. |
| Sierra | open pollinated | 55 | Sister variety to Nevada with red-tinged leaf margins. Same heat tolerance, slightly milder flavor. Striking in mixed-color salad pickings. |
| Cardinale | open pollinated | 55 | Deep red-bronze Batavian, classic French market type. Color intensifies in cool weather and softens in heat. Slightly less bolt-resistant than Nevada but a better-looking head. |
| Concept | hybrid | 50 | Modern F1 with stronger tipburn resistance than the open-pollinated Batavias. Light green tightly-folded heads, more uniform across a planting block. Common in commercial CSA mixes. |
| Magenta | hybrid | 55 | Red Batavian F1 with rosette form and a denser interior than Cardinale. Holds color better in heat and is more bolt-resistant. Useful where you want a red lettuce that won't quit in July. |