Growing Lungwort 'Blue Ensign' in a pot

Pulmonaria 'Blue Ensign' is low-maintenance once established, but consistent moisture and a little feeding keep it vigorous. Water regularly during dry spells in spring and summer, especially if planted in lighter soil or brighter shade. The moderate water need means the soil should stay evenly moist but not sodden; mulching helps retain moisture and reduces watering frequency. In autumn and winter, natural rainfall is usually sufficient. Feed in March or April as new growth emerges. Scatter a general-purpose granular fertiliser (such as blood, fish and bone or Growmore) around the base at the rate recommended on the packet, or apply a 3 cm top-dressing of garden compost or well-rotted manure. This supports flowering and the production of fresh foliage after the June cut-back. Avoid high-nitrogen feeds, which promote soft, mildew-prone growth. Powdery mildew is the most common problem, appearing as white patches on leaves, particularly in dry conditions or where air circulation is poor. The post-flowering foliage cut in June or July usually solves this. Improve air flow by spacing plants properly and avoid overhead watering. Slugs and snails may nibble young leaves in spring; use organic pellets, beer traps, or hand-pick in the evening if damage is severe. Pulmonaria is fully hardy (zone 4–8) and needs no winter protection in temperate Europe. Leave the summer foliage in place over winter for a little insulation, tidying away any collapse in late winter. Divide congested clumps every three to four years in early autumn or spring to maintain vigour. Lift, split with a spade or knife, and replant healthy sections with roots attached.