Lemon balm is a perennial herb that grows best in cool weather. It has lemon-scented, mint-like leaves and spreads prolifically. Start indoors or in the garden in early spring or mid fall. Established lemon balm can tolerate freezing temperatures, but doesn’t do as well in heat. Pick an area with full sun, or an area with moderate shade if you have hot summers. Consider container planting lemon balm - move into shade in warmer weather and back into sun in cooler temperatures.
When starting indoors, start any time for container grown plants or 8 weeks before the last frost date if transplanting outdoors. Lemon balm takes about 14 days to germinate and requires light, so scatter your seeds across the top of your potting soil and gently press in. Avoid covering with top soil, and use grow lights to speed up germination.
Once seedlings are a few inches tall, thin to 8” apart. When transplanting, space plants 18-24” apart.
Lemon balm is a good companion plant to broccoli, cauliflower, and other brassicas, as it helps to deter some pests and attracts pollinators. Add to flower beds and near fruit trees to aid in flower and fruit production, while being deer resistant.
Lemon balm tolerates wetter soil than other herbs, but it can also tolerate drought, once established. Consistent watering and added compost and mulch will cover most needs. In areas with freezing temperatures, cut lemon balm down to 2-3” tall and protect with mulch to ensure the plant grows back from the roots. While not usually bothered by pests, lemon balm can be affected by a few fungal diseases, such as verticillium wilt, mint rust, and powdery mildew. Water at the base of the plant and ensure good air circulation to prevent the majority of problems. Lemon balm can become a host for aphids, scale, and mealy bugs, but these shouldn’t damage the plant and usually a sign of an ant issue. Allow lemon balm to get at least 6-8” tall before harvesting any leaves. Cut back the lowest, oldest branches for the heaviest aroma, and only harvest 1/3 of the plant at any one time. Lemon balm can be used in cooking, tea, drinks, salads, etc!
If planting lemon balm in containers, bring plants in for winter. If you leave plants to flower, cut back dead flowers to reduce self-seeding. Once you have one established plant, don’t be surprised if it starts coming up in random places on its own.