How to grow bunya pine
Overview
Araucaria bidwillii, the bunya pine, is a massive, long-lived conifer from Queensland's subtropical rainforests. It is grown for its stately form, shade, and large, edible seeds contained in heavy, spiky cones. A single tree can dominate a landscape for centuries and requires ample space and caution due to falling cones.
Soil Preparation
Prefers deep, well-drained loam or sandy loam with a pH of 5.5–7.0. Enrich with compost or aged manure before planting. Avoid heavy clay or waterlogged soils; if necessary, improve drainage with raised beds or mounds. No lime needed.
Growing Guide
Plant bunya pine in a deep, well-drained soil in full sun, with at least 10–15 metres clearance from buildings and paths. Dig a hole twice the width of the root ball, backfill with native soil, and water in thoroughly. Space trees 15–20 metres apart. Young trees need consistent moisture for the first 3–5 years; after that, they are drought-tolerant. Do not plant near overhead power lines or high-traffic areas.
Sowing
Sow fresh seeds (from fallen cones) directly in spring or early summer. Plant 2–3 cm deep in a seed-raising mix, keep moist, and expect germination in 4–8 weeks. Seeds are large and can be direct-sown in final position, but transplanting is also successful. Do not let seeds dry out.
Care
Feed with a slow-release native fertiliser (low phosphorus) in early spring and again in autumn. No pruning is required; remove lower branches only for safety or access. Keep a 1–2 metre mulch ring around the base to retain moisture and suppress weeds, but avoid piling mulch against the trunk.
Companion Planting
Bunya pine is a dominant feature tree best planted alone or with other large native trees like hoop pine (Araucaria cunninghamii) or Queensland kauri (Agathis robusta). Avoid planting small, delicate shrubs or fruit trees directly beneath its canopy, as falling cones can cause damage and the dense shade limits understory growth.
Common Pests & Risks
Bunya pine is generally pest-free in Australian gardens. Occasional scale insects (e.g., Eriococcus araucariae) can cause sooty mould; treat with horticultural oil in early spring. Root rot (Phytophthora) may occur in poorly drained soils; ensure good drainage and avoid overwatering. No other significant pests.
Harvesting
Harvest bunya nuts from cones that have fallen to the ground, usually in late summer to autumn (January–March). The cones are large, heavy, and spiky; wear gloves and a hard hat when collecting. Nuts are ready when the cone scales separate easily and the nut inside is firm and brown. Store in a cool, dry place for up to 6 months.
In the Kitchen
Bunya nuts are starchy and nutty, best boiled or roasted. Remove the hard outer shell and inner skin before eating. They can be ground into flour for baking or used in savoury dishes. Store in a cool, dry place for up to 6 months.
Troubleshooting
Yellowing needles: often due to poor drainage or overwatering; check soil and reduce water. Brown needle tips: may indicate salt burn or wind scorch; mulch and protect from strong winds. Stunted growth: usually from insufficient sun or poor soil; ensure full sun and feed with native fertiliser. Cone drop too early: can be caused by drought stress; water deeply during dry spells. Scale insects: treat with horticultural oil.