Growing English lavender 'Munstead' in a pot

Once established, 'Munstead' lavender is remarkably self-sufficient. Water sparingly: in a typical year, rainfall alone suffices. During prolonged summer drought, a deep soak every two to three weeks is enough—overwatering causes root rot and yellowing foliage. In autumn and winter, stop watering entirely unless the plant is in a container. Feed lightly in March or April with a general-purpose granular fertiliser, such as blood, fish and bone, scattered around the base at a handful per plant. Alternatively, use a slow-release balanced feed. Avoid high-nitrogen fertilisers, which promote soft, sappy growth prone to frost damage and poor flowering. Lavender evolved on poor Mediterranean hillsides and actually flowers better in lean soil, so resist the urge to overfeed. 'Munstead' is evergreen and fully hardy in zones 5–9, requiring no winter protection in temperate Europe. Good drainage is far more critical to winter survival than cold itself—wet soil kills lavender faster than frost. In exposed gardens, a gravel mulch helps, but avoid covering the foliage. Pests are few: rosemary beetle and its larvae occasionally chew foliage in late summer; pick them off by hand. The main disease risk is root rot (Phytophthora) in poorly drained soil, which causes sudden wilting and browning. Prevention is key—there's no cure once rot sets in. Powdery mildew can appear in humid, crowded conditions; ensure good air circulation and avoid overhead watering. Harvest flower spikes in June, July or August just as the lowest florets open, cutting in the morning after dew has dried for the best fragrance.