How to grow crepe myrtle
Overview
Crepe myrtle is a deciduous tree grown for its summer flower display, autumn leaf colour, and sculptural bark. It thrives in hot, sunny positions and is a key structural plant in Australian and New Zealand gardens.
Varieties
- Lagerstroemia indica 'Natchez' — White flowers, cinnamon-coloured bark, and excellent heat tolerance.
- Lagerstroemia indica 'Tuscarora' — Coral-pink flowers and a compact, upright habit.
- Lagerstroemia indica 'Zuni' — Lavender flowers and a smaller, shrubby form.
Soil Preparation
Crepe myrtle prefers well-drained, slightly acidic to neutral soil (pH 6.0–7.0). If soil is heavy clay, amend with gypsum and compost to improve drainage. Avoid waterlogged sites.
Growing Guide
Plant crepe myrtle in a hole twice as wide as the root ball, ensuring the top of the root ball is level with the soil. Space trees 3–5 m apart for good canopy development. Water deeply at planting, then reduce to once a week. Do not overwater; allow the soil to dry between waterings to encourage deep roots.
Care
Feed with a slow-release fertiliser in early spring and again after summer flowering. Prune lightly in late winter to remove spent flower heads and shape the canopy; avoid heavy cutting back. Mulch around the base with organic matter to retain moisture and suppress weeds.
Companion Planting
Underplant with lavender, rosemary, or salvia for a dry, sunny border. Avoid planting beneath dense shade trees or near lawns that require frequent watering, as crepe myrtle prefers a drier root zone.
Common Pests & Risks
Powdery mildew appears in humid, still conditions; improve air flow by pruning open centres. Scale insects can be controlled with horticultural oil in winter. Aphids may cause sooty mould; treat with a strong water spray or insecticidal soap.
Troubleshooting
Yellow leaves: overwatering or poor drainage—reduce watering frequency. Brown leaf edges: salt burn from fertiliser or dry winds—flush soil and mulch. Powdery mildew on leaves: poor air circulation—prune for openness. No flowers: too much shade or over-fertilising—move to full sun and reduce nitrogen. Sooty mould on leaves: aphid or scale infestation—treat with oil.