Skip to content

How to Grow Starfruit

Averrhoa carambola

Perennial

Starfruit is a compact tropical evergreen tree that needs a heated greenhouse in the UK with a minimum of 12C over winter. Give it full sun for best fruiting, keep soil consistently moist without waterlogging, and maintain good humidity by misting or using a humidity tray. Starfruit is a heavy feeder — apply a slow-release granular feed in spring and supplement with monthly liquid fertiliser, switching to high-potash when fruiting. It responds well to pruning and can be kept compact in a large container.

Yearly Lifecycle

|
JanFebMarAprMayJunJulAugSepOctNovDec
Flowering Fruit Set Harvest

Care Essentials

Feed monthly with a balanced liquid fertiliser throughout the year. Starfruit is a heavy feeder — apply a slow-release granular feed in spring and switch to high-potash when fruiting. Do not stop feeding entirely in winter as the tree may continue growing under supplementary lighting.

Watch For

  • Glasshouse red spider mite — the most common pest; stippled leaves and fine webbing
  • Scale insects on stems and older woody growth
  • Mealybugs in leaf axils and on stems
  • Anthracnose on fruit and leaves in humid poorly ventilated conditions
  • Root rot from overwatering, especially in winter

Track your Starfruit care schedule — pruning, feeding, and seasonal tasks

Start planning free

Care Requirements

☀️ Light

Full sun; heated greenhouse in UK

Needs full sun for best fruiting. In the UK, grow in a heated greenhouse or large conservatory with maximum light. Tolerates partial shade but will fruit less.

💧 Watering

Keep consistently moist; maintain good humidity

Water regularly to keep soil consistently moist. Starfruit does not tolerate drought or waterlogging. Maintain good humidity by misting or using a humidity tray.

🌱 Fertilizing

Monthly liquid feed; heavy feeder, extra potash for fruit

Feed monthly with a balanced liquid fertiliser during the growing season. Starfruit is a heavy feeder — apply a slow-release granular feed in spring and supplement with high-potash feed when fruiting.

✂️ Pruning

Prune late winter; responds well to size control

Prune in late winter to maintain shape and control size. Remove dead, crossing, or inward-growing branches. Responds well to pruning and can be kept compact in a large container.

❄️ Overwintering

Minimum 12°C; supplementary winter light helpful

Not frost hardy. Maintain a minimum of 12°C over winter. Keep in a heated greenhouse with supplementary lighting. Reduce watering slightly but maintain humidity.

Growing Tips

Feed generously

Starfruit is a heavy feeder — apply slow-release feed in spring and supplement with monthly liquid fertiliser.

Moist but not wet

Keep soil consistently moist and maintain good humidity; starfruit tolerates neither drought nor waterlogging.

Prune to control size

Prune in late winter to control size; starfruit responds well to pruning and can be kept compact in a large container.

Winter lighting helps

Provide supplementary lighting in winter to compensate for the UK's short days and maintain growth.

Pests & Diseases

Pest Glasshouse Red Spider Mite

Identification: Fine stippling on upper leaf surfaces. Leaves become dull and bronzed. Fine webbing visible in severe infestations.

Organic treatment:
  • Introduce the predatory mite Phytoseiulus persimilis
  • Mist foliage regularly to raise humidity
  • Spray with insecticidal soap
Chemical treatment:
  • Spray with a miticide if biological control is insufficient
Pest Scale Insects

Identification: Small brown or white oval bumps on stems and leaf undersides. Sticky honeydew and sooty mould on foliage.

Organic treatment:
  • Scrub off with a soft brush dipped in soapy water
  • Apply a winter plant oil wash
  • Encourage parasitic wasps
Chemical treatment:
  • Spray with a plant oil-based insecticide
Pest Mealybugs

Identification: White, waxy, cottony clusters in leaf axils and on stems. Sticky honeydew and sooty mould.

Organic treatment:
  • Dab individual bugs with a cotton bud soaked in methylated spirit
  • Introduce the ladybird Cryptolaemus montrouzieri as biological control
  • Spray with insecticidal soap
Chemical treatment:
  • Spray with a systemic insecticide containing acetamiprid
Disease Anthracnose Colletotrichum gloeosporioides

Symptoms: Dark, sunken spots on fruit and leaves. Fruit may rot before ripening. Leaves develop brown patches and may drop.

Treatment: Remove and destroy affected fruit and leaves. Improve air circulation.

Prevention: Avoid overhead watering. Ensure good ventilation in the greenhouse. Remove fallen debris promptly.

Disease Root Rot Phytophthora spp.

Symptoms: Yellowing leaves, wilting despite moist soil, dark discolouration at the stem base. Roots are brown and mushy.

Treatment: Reduce watering. Repot into fresh, well-drained compost. Cut away affected roots.

Prevention: Use well-drained compost with added perlite. Avoid overwatering. Ensure containers have adequate drainage holes.

Spacing & Planting

Plant spacing 550 cm
Row spacing 650 cm
Mature height 600 cm
Mature spread 400 cm

Also called carambola. Compact evergreen tree. Multiple flowering flushes year-round. Fast fruit development (60-75 days).

Try our spacing calculator →

Log Starfruit in your garden — track growth, care, and harvests year after year

Start planning free