Lemon balm
Melissa officinalis
Also known asMelissa · Bee balm (regional) · Sweet balm · Bee balm (regional, not Monarda)
Environment
The bounded range this crop tolerates.
Climate and zones
- USDA zones
- 4–9 (winter low around -34°C)
- Frost
- very hardy (survives deep cold)
- Season
- cool (spring/fall)
Growing systems
Root mass: moderate.
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 | 1.5 |
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
One of the easiest perennial herbs for hydroponic growing. EC 1.0-1.8 mS/cm. pH 5.5-7.0. Temperature: 10–28°C (very adaptable; cold-hardy to zone 4). Low to moderate light (DLI 10-18 mol/m2/day; tolerates shade better than most herbs). Any hydroponic system works. From seed to first harvest: 6-8 weeks. From division of existing clump: immediately harvestable. Harvest by cutting stems 5–8 cm above the base; the plant regrows rapidly. A single clump provides harvests every 2-3 weeks indefinitely. The vigorous spreading habit means lemon balm can overwhelm neighbors in a mixed herb planting; give it its own container or section. For tea: steep 8-10 fresh leaves in hot water for 5-10 minutes. The fresh tea is significantly more aromatic than dried. For drying, cut whole stems and hang in bundles or dehydrate at 35–40°C. The essential oil dissipates relatively quickly from dried leaves, so use dried lemon balm within 3-6 months. A low-maintenance, long-lived herb that earns its space through continuous production and culinary versatility.