How to grow climbing hydrangea
Overview
Climbing hydrangea (Hydrangea anomala) is a deciduous woody vine that clings to walls and trunks via aerial rootlets. It is grown to soften vertical surfaces, add lush foliage, and produce creamy lacecap flowers in late spring. Key for Australian growers: it is slow to establish but very cold-hardy, and needs a cool, shaded position to thrive.
Soil Preparation
Climbing hydrangea prefers neutral to slightly alkaline soil (pH 6.5–7.5). Enrich planting holes with well-rotted compost or leaf mould. Ensure the soil is free-draining—soggy roots cause crown rot. On heavy clay, add gypsum and raise the bed.
Growing Guide
Plant climbing hydrangea against a cool, south- or east-facing wall or fence in well-drained, humus-rich soil. Space 1–2 m apart if covering a large area. Provide a deep watering every 7–10 days during the first two summers to encourage root spread. Mulch with bark or compost to keep roots cool. Avoid hot afternoon sun—leaves will scorch and growth stalls.
Care
Feed with a balanced slow-release fertiliser (e.g. 10-10-10) in early spring as buds swell. Prune only to remove dead or wayward stems after flowering—heavy cutting delays regrowth for years. No regular training needed once the vine has attached to its support.
Companion Planting
Good companions include shade-loving ferns (e.g. Dryopteris), hostas, and hellebores planted at the base. Avoid placing near vigorous climbers like wisteria or jasmine that may compete for wall space and light.
Common Pests & Risks
Scale insects can appear on stems in humid spells—treat with horticultural oil in early spring. Leaf spot (Cercospora) shows as brown blotches; improve air circulation and avoid overhead watering. Aphids may cluster on new growth; blast off with water or use a soft soap spray.
Troubleshooting
Leaves turn yellow with green veins: iron deficiency in alkaline soil—apply chelated iron. Brown leaf edges: scorch from hot afternoon sun—move to deeper shade or shield with a screen. No flowers after 5 years: plant may be too young or in too much sun; ensure cool, moist conditions. Stems fail to attach: wall surface too smooth or painted—provide a trellis or wire mesh for the first 2–3 years. Sparse growth: root competition from nearby trees—dig a wider planting hole and add extra compost.