Columbine in April: monthly care

Columbine thrives in partial shade or full sun, though in warmer gardens a spot with afternoon shade will help prolong flowering and prevent leaf scorch. It tolerates a wide range of soils but performs best in loam or chalky soil that drains freely yet retains some moisture. Before planting, dig over the bed to a spade's depth and work in a generous amount of garden compost or well-rotted manure to improve structure and fertility. You can plant container-grown columbine in March, April, May, September or October. Spring planting gives plants a full season to establish, while autumn planting allows roots to settle in before winter. Space plants 30 cm apart to allow for their mature spread of 30–40 cm. Dig a hole slightly larger than the root ball, set the plant so the crown sits level with the surrounding soil, and firm in gently. Planting too deep can lead to crown rot, especially in heavy soils. Water thoroughly after planting to settle the roots and eliminate air pockets. Apply a 5 cm layer of organic mulch—leaf mould or composted bark—around the base, keeping it clear of the crown itself. This conserves moisture, suppresses weeds and keeps roots cool in summer. If planting in autumn, mulching also offers a degree of winter protection, though columbine is extremely hardy (zone 3a–8b) and rarely suffers frost damage. Columbine can also be grown from seed sown outdoors in late spring or early summer, but germination can be erratic and seedlings may not come true to colour if parent plants have cross-pollinated. For reliable colour and quicker results, container-grown plants are the better choice.

Columbine has a moderate water need and prefers soil that stays evenly moist but never waterlogged. Water regularly during dry spells in spring and summer, especially while plants are flowering or newly planted. Once established, columbine tolerates short periods of drought, though prolonged dryness will cause foliage to wilt and flowering to suffer. In autumn and winter, natural rainfall is usually sufficient. Feed in March and April to support strong growth and abundant flowers. Scatter a general-purpose granular fertiliser such as blood, fish and bone around the base of each plant at the manufacturer's recommended rate, then water in. Avoid high-nitrogen feeds, which promote lush foliage at the expense of flowers. A second, lighter feed immediately after flowering can help replenish the plant, but is not essential. Columbine is fully hardy and needs no winter protection in temperate Europe. The crown may remain semi-evergreen in mild winters, but even if top growth dies back completely the plant will reshoot reliably in spring. Mulch around the base in autumn with garden compost or leaf mould to suppress weeds and improve soil structure. The most common pest is the columbine sawfly, whose pale green larvae skeletonise leaves in late spring and early summer. Inspect plants regularly and pick off larvae by hand, or spray with an organic insecticide if infestations are severe. Powdery mildew can appear on foliage in dry summers; improve air circulation by thinning congested clumps and water at the base rather than overhead. Leaf miners occasionally tunnel through leaves, causing pale blotches; remove and destroy affected foliage promptly.