How to grow illawarra plum
Overview
Illawarra plum (Podocarpus elatus) is a slow-growing, evergreen shrub native to eastern Australia. It is grown for its attractive foliage and edible purple fruit, which ripen in late summer to autumn. A key point for growers is that this is a dioecious plant—both male and female specimens are needed for fruit production.
Soil Preparation
Prefers well-drained, loamy soil with a pH of 5.5–6.5. Incorporate compost or aged pine bark before planting. Avoid heavy clay; if soil is poor, raise beds or add gypsum for drainage.
Growing Guide
Plant Illawarra plum in a sheltered position with part shade, especially protection from harsh afternoon sun. It prefers well-drained, slightly acidic soil enriched with organic matter. Space plants 2–3 m apart to allow for their eventual spread. Water regularly during establishment, but once settled, it is moderately drought-tolerant. Avoid heavy clay or waterlogged sites.
Sowing
Seeds are slow to germinate (3–6 months) and require fresh, ripe fruit. Sow 1 cm deep in seed-raising mix, keep moist and warm. Direct sowing is unreliable; transplanting is preferred.
Care
Feed with a slow-release native fertiliser in early spring and again in autumn. Lightly prune after harvest to shape and remove dead or crossing branches. Maintain a thick organic mulch layer to keep roots cool and suppress weeds.
Companion Planting
Good companions include native shrubs such as lilly pilly, blueberry ash, and native ginger. Avoid planting near vigorous root competitors like eucalypts or large acacias, which may outcompete for moisture.
Common Pests & Risks
Scale insects can appear on stems and leaves; treat with horticultural oil in early spring. Birds are the main fruit thieves—netting may be needed. Occasional fungal leaf spot can occur in humid conditions; improve air circulation.
Harvesting
Harvest fruit when it turns deep purple to black and yields slightly to pressure, typically from late summer to autumn. Only pick from confirmed female plants that have been pollinated. Use promptly or freeze for later use.
In the Kitchen
The fruit has a sweet, resinous flavour—eat fresh, or use in jams, sauces, or desserts. Remove the large central seed before cooking. Store ripe fruit in the fridge for up to a week.
Troubleshooting
Yellow leaves: often caused by waterlogged soil or nutrient deficiency—improve drainage and feed with native fertiliser. Brown leaf edges: usually from salt spray or dry winds—provide shelter. Slow growth: common in poor soil or deep shade—add organic matter and ensure part sun. Fruit drop: may indicate lack of pollination or water stress during fruiting.