Growing Lemon balm in a pot

Lemon balm is a low-maintenance herb once established, requiring only moderate watering and minimal feeding. Water regularly during dry spells in spring and summer, aiming to keep the soil evenly moist but never waterlogged. In hot weather, plants in full sun may need watering once or twice a week, while those in partial shade or heavier soils will need less. Reduce watering significantly in autumn and winter when growth slows. Mulching around the base in spring with garden compost helps retain moisture and adds a gentle nutrient boost. Feed lemon balm lightly in April with a general-purpose organic fertiliser or a sprinkling of blood, fish and bone worked into the soil surface. Avoid high-nitrogen feeds later in the season, as these promote soft, sappy growth that is more susceptible to disease and less hardy going into winter. Lemon balm is not a heavy feeder and too much fertiliser can reduce the intensity of its lemon fragrance. This herb is fully hardy in zones 4–9 and requires no special winter protection in temperate Europe. The top growth dies back in late autumn; cut it down to ground level in November and the plant will reshoot vigorously from the base in spring. A light mulch of compost over the crown provides extra insulation in colder areas but is not essential. Lemon balm is generally pest-free, though aphids occasionally cluster on young shoots in spring—wash them off with a jet of water. Powdery mildew can appear on older leaves in humid conditions, particularly if plants are overcrowded or not pruned regularly. Good air circulation and cutting back congested growth in June and August minimise this problem.