Rosemary
Salvia rosmarinus
Also known asGarden rosemary · Romarin · Romero
Environment
The bounded range this crop tolerates.
Climate and zones
- USDA zones
- 7–10 (winter low around -18°C)
- Frost
- tolerates light 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 |
| 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 | 2 | 1 | 2 | 1.2 |
Aquaponics suitability
Not recommended
Fish waste alone doesn't supply enough of what this crop demands. Grows in hybrid systems with supplemental dosing, but expect active management.
Care notes
A long-lived perennial herb for container or hydroponic growing. Container (15 L) with very well-drained media (perlite, pumice, or expanded clay; rosemary dies in waterlogged conditions). EC 1.0-1.8 mS/cm (light feeder). pH 6.0-7.5 (tolerates slightly alkaline). Temperature: 10–30°C (Mediterranean; cold-hardy to zone 7-8 depending on variety). Full sun (DLI 18-28 mol/m2/day). Growth is slow to moderate. Harvest by cutting stem tips (10–15 cm); the plant branches freely when pruned. The woody habit means rosemary doesn't grow back from bare, leafless wood; always cut above green growth. For drying: strip leaves from stems, dry at 35–40°C or hang in bundles. Dried rosemary retains excellent flavor for 12+ months. Propagation by semi-hardwood cuttings (taken in summer, root in 3-6 weeks in moist perlite). From seed is possible but very slow and germination is poor. Overwatering and poor drainage are the primary causes of failure. In a hydroponic herb setup, rosemary needs drier conditions than basil or mint.