How to grow natal plum
Overview
Natal plum (Carissa macrocarpa) is a dense, thorny evergreen shrub grown for its ornamental white flowers and edible red fruit. It thrives in warm, coastal conditions with minimal water and tolerates salt spray and poor soils.
Varieties
- Carissa macrocarpa 'Natal Plum' — Standard form with large, sweet red fruit and dense thorny growth.
- Carissa macrocarpa 'Fancy' — Compact variety with smaller fruit, suited to pots and small gardens.
Soil Preparation
Prefers slightly acidic to neutral pH (6.0–7.0) in sandy or loamy soil. Improve drainage by adding coarse sand or gravel if clay-heavy. Avoid waterlogged sites—raised beds or mounds help in wet areas.
Growing Guide
Plant in full sun in well-drained sandy or loamy soil; space 1.5–2 m apart. Dig a hole twice the width of the root ball, backfill with native soil, and water in well. Mulch lightly to retain moisture but keep away from the stem. Avoid overwatering—established plants need only occasional deep watering.
Sowing
Sow seeds 5 mm deep in seed-raising mix, keep moist at 20–25°C; germination takes 2–4 weeks. Direct sow in spring or early summer in warm zones, or start in pots for better control. Thin to 1 m apart after true leaves appear.
Care
Feed with a balanced slow-release fertiliser (e.g., 8-4-10) in early spring and again after summer fruiting. Prune lightly after harvest to shape and remove dead wood; wear thick gloves for thorns. Monitor for scale and treat with horticultural oil if needed.
Companion Planting
Plant near rosemary, lavender, or coastal banksia for similar dry conditions. Avoid heavy feeders like citrus or vegetables that require frequent watering, as they compete poorly with natal plum's low-water needs.
Common Pests & Risks
Scale insects and fruit fly are common. For scale, apply horticultural oil in early spring before new growth. For fruit fly, use eco-friendly traps or netting on fruiting bushes; remove fallen fruit promptly.
Harvesting
Harvest fruit when fully red and slightly soft to the touch, typically 2–3 months after flowering. Pick by hand or snip with secateurs; wear gloves to avoid thorns. Use immediately or refrigerate for up to a week—unripe fruit is toxic.
In the Kitchen
Use ripe fruit fresh in jams, jellies, or desserts—sweet-tart flavour similar to cranberry. Store in fridge for up to a week; do not eat unripe fruit. Seeds are edible but best strained out for smooth preserves.
Troubleshooting
Yellow leaves: overwatering or poor drainage—reduce water and improve soil. Brown leaf edges: salt burn or wind damage—move to sheltered spot or rinse soil. Fruit drop: inconsistent watering or fruit fly—maintain even moisture and use traps. Thorns: always present—wear gloves when handling.