Caring for Masterwort

Masterwort is a low-maintenance perennial once established, but consistent moisture is the key to success. Water regularly during dry spells, especially from late spring through summer when the plant is actively growing and flowering. The soil should stay evenly moist but not waterlogged. In autumn and winter, natural rainfall is usually sufficient, though you may need to water during prolonged dry periods in spring. Feed in March or April as new growth emerges. A single application of a balanced general-purpose fertiliser or a handful of blood, fish, and bone scattered around the base of each plant is enough. Alternatively, top-dress with a 3–5 cm layer of well-rotted compost or manure in early spring, which feeds the soil and helps retain moisture. Avoid high-nitrogen feeds, which promote lush foliage at the expense of flowers. Mulch annually in spring with organic matter to suppress weeds and keep roots cool and moist during summer. Refresh the mulch layer if it breaks down significantly by midsummer. Masterwort is hardy to zone 4a, so overwintering in temperate European gardens is straightforward. No protection is needed; simply cut back dead foliage in late autumn or early spring as described in the pruning section. Pests are rarely a problem, though slugs and snails may nibble young foliage in spring—use your preferred control method if damage is severe. Powdery mildew can occasionally appear on leaves in dry conditions, particularly if the soil dries out. Keeping the soil moist and ensuring good air circulation usually prevents this. Remove affected leaves if mildew does develop.