How to grow lemon balm
Overview
Lemon balm (Melissa officinalis) is a perennial herb in the mint family, prized for its lemony scent and flavour. It is grown for culinary use, tea, and as a pollinator attractant, and thrives with regular harvesting to keep it bushy.
Varieties
- Lemon balm — Standard form with strong lemon scent, widely available.
Soil Preparation
Lemon balm prefers a slightly acidic to neutral pH (6.0–7.0) in rich, well-draining soil. Amend with compost or well-rotted manure before planting. Good drainage is essential to prevent root rot.
Growing Guide
Plant lemon balm in a position with morning sun and afternoon shade, especially in warmer zones. Space plants 30–45 cm apart in well-draining soil enriched with compost. Water regularly to keep soil evenly moist but not waterlogged. Pinch out growing tips regularly to encourage branching and prevent leggy growth.
Sowing
Sow lemon balm seed 3 mm deep in seed trays or direct in spring. Germination takes 10–14 days at 18–22°C. Thin seedlings to 30 cm apart. Transplant when 10 cm tall.
Care
Feed lemon balm with a balanced liquid fertiliser every 4–6 weeks during active growth. Prune regularly to prevent flowering and maintain leaf quality. Remove spent flower heads to control self-seeding.
Companion Planting
Lemon balm is excellent near fruit trees like apple and citrus to attract pollinators. It also pairs well with brassicas, repelling some pests. Avoid planting near fennel, which can inhibit its growth.
Common Pests & Risks
Aphids and spider mites can attack lemon balm, especially in dry conditions. Control aphids with a strong water spray or insecticidal soap. Spider mites are deterred by keeping humidity up and hosing off the foliage.
Harvesting
Harvest lemon balm leaves just before the plant flowers for the best flavour and essential oil content. Pick individual leaves or cut whole stems back to 5 cm above the ground. Regular harvesting encourages fresh, tender growth.
In the Kitchen
Use fresh lemon balm leaves in salads, teas, and as a garnish. The leaves can be dried for later use, but flavour is best fresh. Store in a sealed container in the fridge for up to a week.
Troubleshooting
Yellow leaves: overwatering or poor drainage. Brown leaf edges: underwatering or too much sun. Leggy growth: not enough light or infrequent pruning. Powdery mildew: poor air circulation. Stunted growth: root competition from nearby plants.