Kari Starfruit (Averrhoa carambola)
Kari is a classic “backyard tropical” starfruit—lush canopy, pretty clusters of pink-lavender blooms, and those ribbed fruits that turn into perfect stars the moment you slice them. When it’s happy, this tree can produce in waves, so you’re not just harvesting once—you’re checking the branches, spotting yellowing fruit, and bringing in fresh stars for the kitchen again and again.
The secret to enjoying starfruit is ripeness. Pick it too early and the flavor is sharp and thin. Let it color up and the fruit becomes juicier and noticeably sweeter. Kari is typically grown for that sweeter eating experience when harvested at the right stage.
In Florida planting zone 9, treat starfruit like a “protected tropical.” Give it sun, steady moisture, a thick mulch zone, and a warm microclimate out of winter wind. Do that, and Kari becomes one of the most rewarding fruit trees you can trial—because it’s productive, beautiful, and the harvest is genuinely fun.
Any reference to medicinal or culinary use of plants or plant parts should in no way be considered an endorsement by The Ocala Food Forest or its staff. Research is crucial in safe and proper consumption or experimentational use of any plant.
Plant Information
| Scientific Name: | Averrhoa carambola (cultivar commonly sold as “Kari”) |
|---|---|
| Family Name: | Oxalidaceae (Oxalis / wood-sorrel family) |
| Common Name(s): | Starfruit, Carambola, Kari Starfruit |
| Size: | Typically 10–25 ft in cultivation (often maintained 8–12 ft with pruning); spreading canopy |
| Plant Type: | Evergreen to semi-evergreen tropical fruit tree |
| Origin/Geographic Distribution: | Native to tropical Southeast Asia; cultivated in tropical/subtropical regions worldwide |
| Native to: | Tropical Southeast Asia |
| Planted range in the USA: | Most successful in South Florida; grown in protected microclimates or containers farther north |
| Conservation Status: | Not listed as threatened or endangered (cultivated fruit tree) |
Cultivation
| Planting: | Plant in spring after the last cold snaps so roots establish before winter; avoid low spots where cold air pools |
|---|---|
| Sun Exposure: | Full sun for best bloom and fruit; light afternoon shade is fine in very hot, reflective sites |
| Soil Type: | Well-drained loam/sandy loam enriched with compost; avoid chronic waterlogging |
| Soil pH: | 5.5 to 6.5 (slightly acidic preferred; near-neutral can work with micronutrient support) |
| Water Requirements: | Moderate to high; keep evenly moist during flowering/fruit fill—mulch helps prevent fruit drop from stress |
| Fertilizer Requirements: | Moderate; feed during warm months with a balanced fruit-tree fertilizer. Watch for iron/manganese chlorosis in higher pH soils. |
| Pruning Requirements: | Prune to maintain a compact canopy, improve airflow, and keep harvest height manageable; tip-prune after harvest flushes |
| Growth Rate: | Medium to fast in warm weather with steady moisture (often 1–3 ft/year once established) |
| Companion Planting: | Use living mulches, nitrogen-fixers, and pollinator plants outside a clear trunk ring to build soil and reduce weeds |
Tolerance and Hardiness
| Drought Tolerance: | Low to moderate; drought stress often causes flower/fruit drop—mulch + consistent watering matter |
|---|---|
| Frost Tolerance: | Low; damage often begins near 32°F (0°C). Severe damage around 30°F (−1°C). Trees can be killed near 27°F (−3°C), especially if cold is prolonged |
| Heat Tolerance: | High; handles 100°F (38°C) well with irrigation. Above 105°F (41°C) can cause stress/sunscald if dry or reflective |
| Wind Tolerance: | Low to moderate; strong winds can strip leaves and drop flowers/fruit—wind protection improves set |
| Salt Tolerance: | Low to moderate; avoid direct salt spray and saline irrigation |
| USDA Plant Hardiness Zones: | Typically 10–11 (best). Can be grown in 9 with a warm microclimate + freeze protection |
Flower and Fruit Information
| Fruit Type: | Fleshy fruit with 5 prominent ribs (slices form a star shape) |
|---|---|
| Harvest Time: | Warm-season through fall (often multiple flushes). Harvest when mostly yellow and the ridges begin to soften/round |
| Fruit Description: | Crisp, juicy fruit; sweet-tart to sweeter depending on ripeness and growing conditions |
| Edible Plant: | Yes (fruit) |
| Edible Parts: | Fruit flesh (skin is also typically edible when clean and pesticide-free) |
| Medicinal: | Not a primary medicinal plant in a home-garden context; valued mainly as a culinary fruit (see Health & Safety note) |
| Flower Color: | Pink to lavender (small clusters) |
| Flower Shape: | Small blossoms in clusters along young branches |
| Fragrance: | Light to mild |
| Flower Bloom Time: | Warm season (often in waves) |
| Bloom Duration: | Bloom cycles over weeks; fruit develops after successful set |
| Pollination: Self or Other? | Often self-fertile; insect activity and nearby trees can improve fruit set and yield |
Wildlife
| Attracts: | Bees and beneficial insects during bloom; ripe fruit can attract birds and other wildlife |
|---|---|
| Pollinators: | Bees and other small insects that work flower clusters |
| Problematic Pest: | Fruit flies (in some areas), scale insects, aphids, mealybugs, and mites; birds may peck ripe fruit. |
Health and Safety
| Toxic: | Not typically toxic for healthy individuals; however, starfruit is high in oxalates and contains compounds that can be dangerous for people with kidney disease |
|---|---|
| Poisonous Parts of Plant: | No commonly recognized “poisonous” parts for landscape contact; fruit safety depends on human health factors |
| Toxic to Humans: | People with kidney disease or kidney impairment should avoid starfruit (serious reactions have been reported). For others, treat as a normal food and consume in moderation |
| Toxic to Animals: | Not commonly listed as toxic to pets; avoid letting pets binge on large amounts of fruit due to stomach upset risk |
| Plant Diseases to be aware of: | Anthracnose, leaf spot, algal leaf spot, fruit rots, and root rot in poorly drained soils |
Companion Planting
For Kari Starfruit (Averrhoa carambola), companions should help build soil, hold moisture, and attract beneficial insects—without competing tightly at the trunk. Keep a clear mulched ring at the base, then plant support species outside that ring.
Florida Native: Sunshine Mimosa (Mimosa strigillosa)
Zone Range: 8–11
Benefits: Nitrogen-fixing groundcover that supports pollinators and reduces weed pressure.
Use: Use as living mulch outside the trunk ring; trim/mow to keep it from creeping into the trunk zone.
Florida Native: Frogfruit (Phyla nodiflora)
Zone Range: 7–11
Benefits: Tough living mulch that reduces soil splash and supports small pollinators.
Use: Excellent for pathways/edges around fruit trees where you want low maintenance.
Florida Native: Beautyberry (Callicarpa americana)
Zone Range: 6–10
Benefits: Biodiversity and wildlife value; can soften wind at the orchard edge.
Use: Plant on the perimeter so it doesn’t shade the starfruit canopy too heavily.
Florida Friendly: Perennial Peanut (Arachis glabrata)
Zone Range: 8–11
Benefits: Nitrogen-fixing groundcover that suppresses weeds and helps stabilize soil moisture.
Use: Use outside the trunk ring as a tidy living mulch under open-canopy fruit trees.
Florida Friendly: Pigeon Pea (Cajanus cajan)
Zone Range: 9–11 (often grown as an annual in cooler zones)
Benefits: Nitrogen-fixer and biomass producer; can serve as a temporary nurse plant and wind softener.
Use: Plant on the windward side and chop-and-drop for mulch as the starfruit canopy expands.
Florida Friendly: Lemongrass (Cymbopogon citratus)
Zone Range: 9–11
Benefits: Aromatic clumps add mulch material and help define bed edges.
Use: Plant as a border clump away from the trunk zone; harvest routinely to keep it tidy.
Starfruit is sensitive to stress—especially drought and cold wind. Keep moisture steady, mulch wide, and protect from winter exposure. If you’re pushing this tree in zone 9, choose the warmest microclimate you have and be ready to cover the canopy on freeze nights.
Sources & References
Reference list used for general horticultural guidance and Florida-relevant best practices (not medical advice):
- UF/IFAS Extension (Solutions for Your Life) — home fruit tree care in Florida: soils, watering, seasonal timing, and landscape best practices.
- UF/IFAS EDIS Publication Database — research-based references for fruit tree culture, pests/diseases, and Florida-friendly management approaches.
- Florida-Friendly Landscaping™ Program — water-wise, sustainable planting practices that fit food forest systems.
- USDA Plant Hardiness Zone Map — zone reference framework for planting suitability and winter-risk expectations.
- Kew: Plants of the World Online — taxonomy and native-range context for Averrhoa carambola.