How to grow Star Fruit in Australia
Star fruit, or carambola (Averrhoa carambola), is a fast-growing tropical evergreen whose waxy, ribbed yellow fruit cut into perfect stars. Grafted sweet varieties start cropping within a year or so of planting, and a mature tree can bear very heavily. It suits the tropics and frost-free coastal Queensland and northern New South Wales.
📖 Our full guide: How to Grow Star Fruit in Australia
At a glance
When to sow by region
| Region | When to sow | Regional note |
|---|---|---|
| South East Queensland | September to March | |
| Northern Rivers NSW | September to March | |
| Sydney & Coastal NSW | October to January | Marginal tropical; inconsistent fruiting in Sydney; requires sheltered warm microclimate. |
| Melbourne & Victoria | Not suited | Tropical; frost lethal. Melbourne winter unsuitable. |
| Adelaide & SA | Not suited | Mediterranean: unsuitable. Star Fruit tropical; needs year-round warmth. Not viable Adelaide/Perth. |
| Perth & WA | Not suited | Mediterranean: unsuitable. Star Fruit tropical; needs year-round warmth. Not viable Adelaide/Perth. |
| Tasmania | Not suited | Unsuitable. Tropical tree. Not viable in Tasmania. |
| Canberra & ACT | Not suited | Star Fruit unsuitable for Canberra: tropical; frost-intolerant; requires warmth and humidity. Not viable. |
| North Queensland | September to March | Wet season. Star fruit is tropical tree fruit; thrives in heat and humidity. |
| Darwin & Top End | September to March | Wet season. Star fruit is tropical tree fruit; thrives in heat and humidity. |
Where to plant
Star fruit needs a warm, frost-free spot in full sun with shelter from strong wind. It is fast growing and its branches break easily, particularly in the first four years, and wind also drops the fruit. It is not fussy about soil, growing in sandy to clay loams, but it prefers deep, well-drained soil and must not sit in waterlogged ground.
It needs plenty of water in dry weather, and high humidity suits it.
- North Queensland and Darwin: thrives. Plant from September to March, in the wet season. Trees can crop several times a year.
- South East Queensland and the Northern Rivers: grows well in frost-free spots. Plant from September to March. Expect one main crop in late summer and autumn.
- Sydney: marginal. Fruiting is inconsistent, so choose the warmest, most sheltered spot and plant from October to January.
- Melbourne, Adelaide, Perth, Hobart and Canberra: not suited.
Choosing a variety
Buy a grafted tree of a sweet variety. Grafted trees bear within about a year, while seedlings are unreliable. Fwang Tung is a well-regarded sweet variety for home gardens, and Wheeler is another sweet type. Sour types are mainly for cooking and preserving.
How to plant
- Choose a sunny, sheltered, well-drained spot with room for a small tree.
- Dig in compost and plant at the same depth as the pot.
- Water in well and mulch a wide band around the tree, keeping mulch off the trunk.
- Stake young trees in windy spots, and water regularly while they establish.
Watering and feeding
Star fruit uses a lot of water. Water deeply and regularly through dry spells, especially while flowering and fruiting, and keep a thick mulch over the root zone. A short dry spell can trigger flowering, but long dry periods reduce the crop.
Feed several times through the warm season with a balanced fruit tree fertiliser that is relatively high in potassium, increasing the amount as the tree grows.
Pruning and care through the year
- Prune young trees to a sturdy, well-spaced framework to reduce limb breakage, and keep the tree compact for easier picking and netting.
- Remove fallen fruit promptly to reduce fruit fly.
- Check for scale on stems and leaves and for leaf-rolling caterpillars on new growth.
Harvesting
Pick fruit when it has turned yellow to golden, the ribs are full colour and the fruit smells sweet. Fruit does not sweeten much once picked, so let it colour well on the tree. Handle it gently, as it bruises easily and the rib edges brown quickly.
Ripe fruit keeps up to about a week in the fridge.
Growing in pots
Star fruit can be grown in a large pot, at least 60 cm wide, in a warm, sheltered spot. It needs regular watering and feeding and will crop less than a tree in the ground.
Using it
Slice star fruit crossways into stars for salads, fruit platters and drinks. The skin is thin and edible. Sour types are used in chutneys, pickles and cooking.
Star fruit is high in oxalic acid and contains a natural toxin that healthy kidneys clear. People with kidney disease should not eat star fruit, as it can make them seriously ill.
Companion planting
Star fruit does well in a tropical fruit garden where taller trees or a windbreak shelter it without shading it.
Good companions
- Tropical fruit trees A mixed tropical orchard or windbreak gives star fruit the shelter its brittle branches need.
Pests and diseases
Fruit fly is the main problem for star fruit in Queensland and the Top End.
Pests to watch for
- Fruit fly Sting marks on the skin and maggots in ripening fruit. Pick promptly, bin fallen fruit, and bag or net fruit in fruit fly areas.
- Scale Small brown or white bumps on stems and leaves, often with sooty mould.
- Caterpillars Leaf-rolling caterpillars webbing new leaves together.
Diseases to watch for
- Anthracnose Dark spots on leaves and fruit in wet, humid weather.
Common questions
Can I grow star fruit in Brisbane?
Yes, in a frost-free, sunny spot sheltered from wind. Expect one main crop in late summer and autumn. In North Queensland and Darwin trees can crop several times a year.
How long does star fruit take to fruit?
Grafted trees usually start fruiting within about 9 to 12 months of planting, with good crops from the second or third year. Seedlings are slower and unreliable.
When is star fruit ripe?
When it has turned yellow to golden, the ribs are fully coloured and it smells sweet. It does not sweeten much after picking, so let it colour well on the tree.
Is star fruit safe to eat?
For most people, yes, in normal amounts. People with kidney disease should not eat star fruit at all, as it contains a natural toxin that damaged kidneys cannot clear, and it is high in oxalic acid.
Why do star fruit branches break?
The tree grows fast and its wood is brittle, especially in the first four years. Plant it out of strong wind, prune to a sturdy framework and thin heavy crops.
Can I grow star fruit in Sydney?
It is marginal. Trees grow in warm, sheltered spots, but fruiting is inconsistent. It is not suited to Melbourne, Adelaide, Perth, Hobart or Canberra.
Sources we checked: Rare Fruit Club archives: Carambola culture in north Queensland (Queensland DPI, 1983); Rare Fruit Club archives: Carambola fact sheet (1984).