How to grow pin cushion hakea
Overview
Pin cushion hakea (Hakea sericea) is an Australian native shrub grown for its prickly foliage and showy pincushion-like flowers that attract birds. It serves as a dense screen or shelter plant in sunny, dry positions. Key need: excellent drainage and full sun to thrive.
Soil Preparation
Prefers slightly acidic to neutral soil (pH 5.5–7). Requires excellent drainage; amend heavy clay with gypsum and coarse sand or plant in raised beds. Incorporates well with gravelly or sandy loam; no need for rich organic matter.
Growing Guide
Plant pin cushion hakea in a sunny, well-drained position. Space plants 1.5–2 metres apart for a dense screen. Prepare soil by improving drainage with gravel or coarse sand if needed. Water sparingly after planting to encourage deep rooting; avoid overhead watering. Mulch lightly with gravel or pebbles, not organic matter that retains moisture.
Sowing
Sow seeds in autumn or spring in well-drained seed-raising mix. Seeds germinate in 3–6 weeks at a depth of 5 mm; keep moist but not wet. Direct sow or start in pots; transplant when seedlings are 10–15 cm tall.
Care
Feed in early spring with a low-phosphorus native fertiliser. Prune lightly after flowering to maintain shape and remove spent blooms. Avoid over-pruning; only remove dead or damaged wood and lightly tip-prune to encourage bushiness.
Companion Planting
Good companion plants include other dry-loving natives like Grevillea, Banksia, and Westringia. Avoid planting near moisture-loving plants or in heavy clay prone to waterlogging. The prickly foliage provides shelter for small birds, so combine with bird-attracting plants like Callistemon.
Common Pests & Risks
Scale insects can occur, particularly on stressed plants. Control by pruning affected branches or applying horticultural oil. Root rot may develop in poorly drained soils, so ensure free-draining conditions. Spider mites can attack in hot, dry conditions; manage with water spray or eco-oil.
Troubleshooting
Yellow leaves: often due to waterlogging or poor drainage; improve soil drainage. Brown leaf tips: caused by high phosphorus fertiliser or salt stress; use native fertiliser. Wilting: possible root rot from overwatering; reduce water and check roots. No flowers after several years: insufficient sunlight or over-fertility; prune to open canopy and ensure full sun. Scale infestation: treat with horticultural oil; prune heavily infested branches.