Buddleja davidii

• Height: 1.5–3 m
• Width: 1.5–2.5 m
• Flowering: July–October
• Light: full sun
• Soil: well-drained, moderately fertile
• Hardiness: zones 5–6, needs winter cover

Planting. Plant in spring or autumn in full sun to part shade in well-drained soil. Dig the hole twice as wide as the root ball and keep the root collar level with the soil surface.

Care. Care is easy: a mulch of peat, bark or compost keeps moisture in and suppresses weeds. Water regularly after planting; later a thorough soaking in dry spells is enough.

Watering and feeding. Water deeply and infrequently rather than often and shallowly. Feed with a balanced fertiliser or compost in spring and stop feeding from mid-July so the shoots ripen before winter.

Winter and pruning. Young plants benefit from winter mulch in the first years. Remove dry and frost-damaged branches in spring before the leaves open; do formative pruning according to how the plant is used. Cut back to 20–30 cm in spring: flowers form on new growth. In a hard winter the shoots may die back to the ground but regrow from the base; mulch the root collar in autumn.