How to grow japanese pittosporum
Overview
Japanese pittosporum (Pittosporum tobira) is a dense, rounded evergreen shrub valued for its glossy, dark green leaves and creamy-white, fragrant spring flowers. It is commonly used as a filler plant, hedge, or screen in coastal and urban gardens, and is highly tolerant of pruning and heat.
Varieties
- Pittosporum tobira 'Variegata' — White-edged leaves add brightness; slower-growing than the species, ideal for small gardens.
- Pittosporum tobira 'Nanum' — Compact dwarf form, reaching 1 m tall; excellent for low hedges or ground cover.
- Pittosporum tobira 'Wheelers Dwarf' — Dense, rounded habit with dark green leaves; very popular for formal hedging in Australia.
Soil Preparation
Prefers well-drained, loamy to sandy soil with a pH of 6.0–7.5. If soil is heavy clay, amend with gypsum and compost to improve drainage. Avoid waterlogged sites — raised beds or mounds help in wet areas.
Growing Guide
Plant in a position with morning sun and afternoon shade, especially in hotter zones. Space 1–1.5 m apart for a dense hedge, or 2–3 m for a specimen shrub. Dig a hole twice the width of the root ball, backfill with native soil, and water in well. Mulch deeply with organic matter, keeping it clear from the stem. Water deeply once a week for the first two summers, then reduce to once every 2–3 weeks once established.
Sowing
Seeds are slow to germinate (4–8 weeks) and require warm, moist conditions. Sow 5 mm deep in seed-raising mix, keep at 20–25°C. Direct sowing is not recommended; transplant seedlings when 10 cm tall. Most gardeners propagate from cuttings or buy nursery plants.
Care
Feed in early spring with a balanced slow-release fertiliser (e.g., 8–9 month NPK 14-14-14). Prune lightly after flowering to maintain shape, removing any dead or crowded branches. For a formal hedge, shear twice a year — once in late spring and again in late summer.
Companion Planting
Plant near paths, driveways, or as a low screen alongside Westringia fruticosa (coastal rosemary) or Myoporum parvifolium. Avoid planting near vigorous, spreading grasses like Pennisetum that may compete for root space and require frequent trimming.
Common Pests & Risks
Scale insects (especially soft brown scale) and sooty mould are the most common issues. Treat with horticultural oil in late winter or early spring before new growth. Monitor for aphids on new shoots in spring; a strong water blast or neem oil spray can control them.
Troubleshooting
Yellow leaves: overwatering or poor drainage — reduce watering and check soil. Brown leaf edges: salt burn from coastal winds or fertiliser excess — flush soil with fresh water. Sparse growth: too much shade — move to brighter spot. Leaf drop: sudden cold snap or frost — protect with frost cloth. Sooty mould on leaves: scale insect infestation — treat with horticultural oil.