How to grow tea tree
Overview
Leptospermum scoparium, commonly known as tea tree or mānuka, is a dense evergreen shrub native to Australia and New Zealand. It is grown for its profuse white, pink, or red flowers in spring and early summer, and its fine, aromatic foliage that provides texture and structure. Key to success is well-drained soil and a sunny to partly shaded position.
Varieties
- Leptospermum scoparium 'Nanum Ruru' — A compact dwarf variety reaching 1 m, ideal for small gardens and containers.
- Leptospermum scoparium 'Red Damask' — Double deep red flowers, very showy, grows to 2–3 m tall.
- Leptospermum scoparium 'Snow White' — Pure white single flowers, vigorous and hardy, reaches 2–3 m.
- Leptospermum scoparium 'Pink Cascade' — Weeping habit with soft pink flowers, excellent for cascading over walls.
Soil Preparation
Tea tree thrives in well-drained, slightly acidic soil (pH 5.5–6.5). Sandy loam or loamy soils are ideal; heavy clay should be amended with gypsum and organic matter to improve drainage. If soil is alkaline, incorporate sulfur or peat moss before planting. Avoid waterlogged conditions.
Growing Guide
Plant tea tree in a sunny or partly shaded position with well-drained, slightly acidic soil. Space shrubs 1–2 metres apart for hedges or 2–3 metres for specimen plants. Dig a hole twice as wide as the root ball, backfill with native soil, and water in well. Mulch lightly to retain moisture but keep mulch away from the stem. Avoid heavy clay or waterlogged sites; if soil is heavy, plant on a mound or raised bed.
Sowing
Sow seeds in spring or autumn in a seed-raising mix, barely covering them as they need light to germinate. Keep moist and warm (18–22°C); germination takes 2–4 weeks. Transplant seedlings when they reach 5–10 cm tall. Direct sowing is not recommended; start in pots or trays for best results.
Care
Feed with a slow-release native fertiliser in early spring, avoiding high-phosphorus blends. Prune lightly after flowering to maintain a compact shape and encourage next season's blooms. Remove any dead or diseased wood as needed. In cooler zones, protect young plants from heavy frost with a light mulch or frost cloth.
Companion Planting
Tea tree pairs well with other Australian natives such as Grevillea, Callistemon (bottlebrush), and Hardenbergia (coral pea). It also complements ornamental grasses like Poa labillardieri and low-growing groundcovers like Myoporum parvifolium. Avoid planting near invasive weeds or plants that require heavy summer watering, as tea tree prefers drier conditions once established.
Common Pests & Risks
Scale insects and webbing caterpillars (e.g., leafroller caterpillars) are common on tea tree. Scale appears as small brown or white bumps on stems and leaves; treat with horticultural oil in early spring. Webbing caterpillars create silken webs and chew foliage; remove by hand or apply Bacillus thuringiensis (Bt) spray. Monitor regularly, especially after flowering.
Troubleshooting
Yellow leaves: often due to waterlogged soil or poor drainage; improve drainage or reduce watering. Brown leaf tips: caused by salt burn from over-fertilising or hard water; flush soil with rainwater and reduce fertiliser. Sparse flowering: insufficient sunlight or over-pruning; ensure at least 4–6 hours of sun and prune only after flowering. Leaf drop: stress from drought or sudden temperature change; maintain consistent moisture and mulch. Scale infestation: treat with horticultural oil; prune heavily infested branches.