How to grow lavender
Overview
Lavender (Lavandula angustifolia) is a woody perennial herb grown for its fragrant flowers, culinary use, and essential oil. It thrives in full sun and sharply drained soil, and is a magnet for bees and beneficial insects.
Varieties
- Lavandula angustifolia 'Hidcote' — Compact, dark purple, excellent for hedges and oil — the standard for Australian gardens.
- Lavandula angustifolia 'Munstead' — Early-flowering, low-growing, ideal for pots and borders in cooler zones.
- Lavandula angustifolia 'Grosso' — High oil yield, very fragrant, popular for drying and sachets in temperate climates.
- Lavandula angustifolia 'Lavender Lady' — A dwarf variety that flowers in its first year from seed, perfect for subtropical and Mediterranean gardens.
Soil Preparation
Lavender needs free-draining, slightly alkaline soil (pH 6.5–7.5). Amend heavy clay with coarse sand, gravel, or horticultural grit. Add a handful of lime or dolomite if soil is acidic. Avoid rich compost or manure — too much nitrogen causes floppy growth.
Growing Guide
Plant lavender in full sun with at least 6 hours of direct light. Space 30–45 cm apart in well-drained, slightly alkaline soil (pH 6.5–7.5). Avoid heavy clay or wet spots; raised beds or mounds improve drainage. Water sparingly once established — let the soil dry between drinks. Prune after flowering to keep plants compact and prevent woodiness.
Sowing
Sow lavender seed 3 mm deep in seed-raising mix, keep at 18–21°C, and expect germination in 14–21 days. Harden off before transplanting. Direct sowing is unreliable; start in punnets or buy plugs. Space 30–45 cm apart in final position.
Care
Feed lavender lightly in early spring with a low-nitrogen fertiliser (e.g., seaweed or bone meal). Prune back by one-third after flowering to maintain a compact shape and prevent woodiness. Remove dead or diseased stems as needed; avoid heavy pruning into old wood.
Companion Planting
Grow lavender near roses, rosemary, thyme, sage, and oregano to repel aphids and whitefly. Avoid planting near mint or brassicas, which can compete for nutrients or attract different pests.
Common Pests & Risks
Root rot and fungal diseases (Phytophthora, Rhizoctonia) strike in wet, poorly drained soil. Prevent with sharp drainage and avoid overwatering. Aphids and spittlebugs may appear in spring; blast off with water or use insecticidal soap. Lavender rarely suffers serious pests in Australian gardens.
Harvesting
Harvest lavender stems when the first few buds on each spike begin to open — this is when oil and fragrance are strongest. Cut early in the morning after dew dries, and hang bunches upside down in a dark, airy spot. Strip dried flowers for sachets, tea, or cooking.
In the Kitchen
Use fresh or dried lavender buds sparingly in shortbread, honey, ice cream, or tea — a little goes a long way. Harvest just before full bloom for best flavour. Store dried flowers in an airtight jar away from light for up to a year.
Troubleshooting
Yellow lower leaves: overwatering or poor drainage — reduce water and check soil. Leggy, floppy growth: too much nitrogen or shade — move to full sun and feed with low-N fertiliser. Few flowers: insufficient sun or over-pruning — ensure 6+ hours of direct light. Grey mould on stems: humid, wet weather — improve air circulation and avoid overhead watering.