Rue
Ruta graveolens
Also known asCommon rue · Garden rue · Herb of grace · Ruda · Pixie
Environment
The bounded range this crop tolerates.
Climate and zones
- USDA zones
- 5–10 (winter low around -29°C)
- Frost
- very hardy (survives deep cold)
- Season
- warm (summer, frost-sensitive)
Growing systems
Root mass: moderate.
Growing media
| Medium | pH effect | Retention | Bacterial surface |
|---|---|---|---|
| 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 | 0.6 |
| vegetative | 2 | 1 | 2 | 1.2 |
Companion-growing notes
- Releases root compounds that can inhibit other crops in a shared reservoir.
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 niche herb for experienced growers interested in historical or Ethiopian cuisine. Container (10 L) with well-drained media. EC 1.0-1.5 mS/cm (very light feeder). pH 6.5-8.0 (tolerates alkaline conditions). Temperature: 15–28°C (Mediterranean; cold-hardy to zone 4). Full sun (DLI 16-22 mol/m2/day). The plant is low-maintenance once established. Harvest individual leaves sparingly (the flavor is intense; a single leaf is typically enough for a dish or drink). Handle with gloves, especially in sunny conditions, because the furanocoumarins in the sap cause painful phytophotodermatitis blisters on skin exposed to UV light. This is the same reaction caused by wild parsnip and giant hogweed. The skin reaction can be severe: avoid contact with sap, and if contact occurs, wash the area immediately and avoid sun exposure for 48 hours. Despite this hazard, rue is a valuable ornamental and historically important herb. The blue-green foliage is attractive in mixed plantings.