How to grow lime
Overview
Lime (Citrus x aurantiifolia) is a compact evergreen tree grown for its aromatic white flowers, glossy leaves, and tangy green fruit. It thrives in warm, frost-free gardens and can be both an ornamental and productive addition to the landscape.
Varieties
- Tahitian — The most common backyard lime in Australia, seedless and vigorous with thin skin.
- Kaffir — Grown for its aromatic leaves used in cooking; fruit is less juicy but very fragrant.
- Australian Finger Lime — Native citrus with elongated fruit and caviar-like pulp; a gourmet favourite.
Soil Preparation
Lime prefers slightly acidic to neutral soil (pH 6.0–7.0). Improve drainage in heavy clay by adding gypsum and organic matter. Before planting, incorporate well-rotted manure or compost and a handful of blood and bone.
Growing Guide
Plant lime in full sun with well-drained soil, ideally a sandy loam. Space trees 3–4 m apart. Water deeply and regularly, especially during fruit set, but avoid waterlogging. Mulch with organic matter, keeping it clear of the trunk. In cooler zones, plant against a north-facing wall or in a pot that can be moved to shelter.
Sowing
Lime is usually grown from grafted nursery trees, not seed. If sowing seed, plant 1 cm deep in seed-raising mix, keep warm and moist. Germination takes 2–4 weeks; seedlings are slow and may not produce true fruit.
Care
Feed lime with a balanced citrus fertiliser in early spring and late summer, high in nitrogen and trace elements like zinc and iron. Prune after harvest to remove dead wood and open the canopy, but avoid heavy cutting. Mulch well to retain moisture and suppress weeds, keeping mulch away from the trunk.
Companion Planting
Plant basil, marigolds, and nasturtiums nearby to repel aphids and attract beneficial insects. Avoid planting near eucalyptus or other trees that compete heavily for moisture and nutrients.
Common Pests & Risks
Common pests include citrus gall wasp (swellings on branches), scale insects (sticky honeydew), leaf miner (curled leaves), and aphids. Control with horticultural oil or neem oil in spring. Prune out gall wasp galls before they hatch. Monitor for sooty mould on honeydew.
Harvesting
Harvest limes when they reach full size and the skin turns from dark green to a lighter greenish-yellow, usually 6–9 months after flowering. Fruit should feel heavy for its size. Pick by cutting with secateurs to avoid damaging the branch.
In the Kitchen
Limes are best used fresh; juice and zest add acidity to drinks, marinades, and desserts. Store at room temperature for a week or refrigerate in a plastic bag for up to three weeks. Freeze juice in ice cube trays for later use.
Troubleshooting
Yellow leaves: often due to nitrogen or iron deficiency; feed with citrus fertiliser and apply iron chelate. Brown leaf edges: salt burn or overwatering; reduce water and check drainage. Fruit drop: caused by inconsistent watering or extreme heat; maintain even moisture. Sooty mould: indicates scale or aphid infestation; control pests first. Gall wasp: prune out swollen stems and destroy.