Pruning Lemon balm

Lemon balm benefits from regular pruning to keep it productive, compact, and prevent it from becoming straggly or self-seeding prolifically around the garden. The main pruning periods are June and August, which coincide with the plant's vigorous growth and flowering phases during summer. In June, once the plant has put on substantial leafy growth, cut it back by about half to two-thirds of its height using clean, sharp secateurs or garden shears. This encourages a fresh flush of tender, flavourful leaves and delays flowering if you want to prioritise foliage production over blooms. If you allow lemon balm to flower—which is beneficial for pollinators—deadhead the spent flower spikes promptly to prevent prolific self-seeding. The small white flowers are attractive but the plant can become invasive if allowed to set seed freely. Prune again in August after the main flowering period. Cut the whole plant back hard to about 10–15 cm above ground level. This rejuvenates the plant, promotes bushy regrowth, and provides a final harvest of fresh leaves before autumn. The new growth will be more compact and less prone to mildew, which can affect older, congested foliage in damp conditions. Use sharp tools to make clean cuts and avoid tearing the stems. You don't need specialist equipment—kitchen scissors or secateurs work perfectly well. If your lemon balm looks tired or diseased at any point during the growing season, don't hesitate to cut it back hard; it recovers quickly and will reward you with healthy new growth within a few weeks.