Table of Contents
What is star fruit? You’ve come to the right place. The star fruit is a rich source of vitamin C, B9, B6, B2, and dietary fiber. It also contains various minerals, such as potassium, zinc, phosphorus, and iron. It’s a low-calorie fruit, with only 31 calories per 100 grams. And the star fruit tree is beautiful, too!
A mature tree can produce as much as 200 to 400 pounds of fruits every year. The star fruit is pulpy with a grape-like texture. The flavor is described as similar to feijoa, but with hints of banana and pear and the acidity of pineapple.
It’s also a widely popular ornamental plant. With beautiful foliage and lovely clusters of lilac-colored flowers, this tree can enhance the aesthetic appeal of your garden. The flowers also attract bees, so it can entice more pollinators to your yard.
Good Products When Caring For A Star Fruit Tree:
- Bonide All-Seasons Horticultural & Dormant Spray Oil
- Safer Brand Insect Killing Soap
- PyGanic Organic Pyrethrin Concentrate
- Serenade Garden Disease Control
- Monterey Liqui-Cop Liquid Copper Fungicide
Quick Care Guide
| Common Name(s) | Starfruit, carambola, five-finger, bilimbi |
| Scientific Name | Averrhoa carambola |
| Days to Harvest | 60 to 75 days after the fruit sets |
| Light | Full sun |
| Water: | Regular watering, 2-3x per week if no rain |
| Soil | Well-draining, many soil types |
| Fertilizer | Depends on age of tree |
| Pests | Scale insects, weevils, stink bugs, squash bugs, thrips |
| Diseases | Fungal leaf spot, algal rust, anthracnose fruit rot, pythium root rot |
All About Star Fruit
The star fruit plant goes by the botanical name Averrhoa carambola. However, the tree and the fruit have many common names in different regions. For example, in Spain and the surrounding areas, the tree is known by the name carambola. In Indonesia, it is called bilimbi, although that name also refers to Averrhoa bilimbi, and thus isn’t used to refer to star fruit often.
The Averrhoa carambola tree is generally multi-branched, with dark-green bushy foliage. It can grow up to 20 to 30 feet in height and 20 to 25 feet wide, but is often maintained in a smaller size for ease of harvest.
It produces small, bell-shaped flowers with five petals. Their color is lilac, but they have purple streaks along the petals. When grown in tropical conditions such as the southern parts of Florida, the plant typically blooms in April and May but may produce a second bloom in September to October. A few scattered flowers can appear year-round.
The star fruit season is long, with harvestable fruit appearing from June sometimes all the way to the following February. Roughly oval in shape, the fruit has deep indentations along its sides. When cut in cross-sections, the indentations make it form a star, hence the name of starfruit. It is usually light to dark yellow in color with slightly darker skin.
There are many types of carambolas, but they fall into one of two categories: sweet, or tart. The tart varieties are generally used as a garnish or in savory applications such as curries or stews. The sweet ones are used for jams and jellies, juicing, cocktails or desserts.
Like other exotic fruits, it may not be for everyone. The starfruit contains enough oxalic acid that it may be potentially risky for people with kidney disease to consume it.
Starfruit hails from tropical Southeast Asia, where it has been cultivated for centuries. It was introduced to the subcontinent and Sri Lanka by Austronesian-speaking traders. Today, it is cultivated and enjoyed almost all over the world, with Australia, Malaysia, Philippines, Taiwan, and the USA being the top producers. India is the biggest producer in Southeast Asia.
Planting Star Fruit Trees
Planting a starfruit tree in your garden can be a lot of fun. Plus, the delicious fruit is well worth it if you’re in the right area to grow it! Here’s some tips on planting these the right way.
When To Plant
As a tropical, the star fruit tree should be planted in locations where frost isn’t likely. Having said that, it’s still wise to plant this tree in the early spring to ensure it has time to settle in prior to the hot months.
If starting a carambola seed, they require warm soil to germinate. Make sure you’re using a seedling heating mat at a temperature of at least 70 degrees to ensure good germination. You’ll likely still need to have young trees container grown for a while before you transplant into the soil, possibly as much as 2-3 years.
Where To Plant
Full sun is necessary for good star fruit growth. Make sure your starfruit tree receives at least 8 hours of sunlight every day, and that it’s sheltered from winds.These plants are not tolerant of high winds, cold climates, or in alkaline soils.
Your tree should be 20-30 feet from any other trees or from structures. This reduces the likelihood of the tree getting too much shade. Similarly, trees that are grown in containers need to be well away from other trees and structures to enable good growth.
How To Plant
Once your plant is roughly 2-4 feet in height and has sized up to at least a 3-gallon container, it’s time to plant it in the soil. Be sure it isn’t rootbound and that it’s in good health. Try planting young trees in Air Pots, as these are expertly-designed to promote the healthiest possible roots.
Prepare your soil in advance by loosening it up in the area where the roots will grow. Do not apply fertilizer, compost, or other additives to the soil. Instead, make sure that if there’s large rocks that they’ve been removed, and that the soil is well-draining and slightly acidic. Plant at the same depth the tree was planted in its pot, but no deeper.
Carambola Care
The carambola is fairly low-maintenance once established, provided you’re giving it the right care. Let’s go over the conditions that your tree wants to produce incredible star fruit!
Sun and Temperature
Carambola plants prefer full sun conditions. The plant prefers a hot and humid environment and is prone to frost damage.Temperatures under 35 degrees get steadily more dangerous, and temperatures below 25 degrees can cause tree death.
When grown outdoors, it performs best in the USDA zones 9 to 11. The temperature must be 60° F or higher for good tree health, and preferably 70-95 for fruit production.
Watering and Humidity
Not a drought-tolerant species, your carambola will need regular watering. Keep the soil moist, but not over-saturated, at all times. Aim for 1-2 deep waterings per week if there hasn’t been rain. Reduce watering in the winter months when it’s unnecessary. A soaker hose around the tree can be used to do a slow, deep watering, but base your placement on a ring that’s at about the midpoint of the tree’s canopy all the way around.
Your tree can tolerate flooded conditions for between 2-10 days, depending on its current health, but will begin to suffer from lack of oxygen around its roots. It’s better to avoid flooding for this species, but if it can’t be avoided, it won’t immediately suffer damage.
Humid environments are great for this species. However, watch for any symptoms of plant diseases that are common in humid locations.
Once your tree is 1-2 years old, consistent irrigation is important from flowering through fruiting. Make sure it has the water it needs to produce lots of fruit.00
Soil
Carambolas do well in a wide variety of soil textures. As long as the soil drains off excess moisture, it should be fine to plant your tree in.
Slightly acid-loving, to grow star fruit you’ll need an acidic to neutral pH range. In more alkaline pH levels, they are susceptible to nutrient deficiencies. Aim for a range between 4.5 and 7 for best growth.
Fertilizing
Carambola trees are moderately-high feeders. Mature trees should be fertilized 4-6 times per year, and young trees every 30-60 days throughout the growing season. Aim for a 6-2-6 or 6-4-6 fertilizer range when possible, preferably one that includes micronutrients such as manganese, iron, zinc, and magnesium.
If your tree is in alkaline soil, it may suffer from nutrient deficiencies. These should receive foliar sprays 4-6 times a year that contain manganese, iron, and zinc.
Pruning
In the first 1-2 years after planting, tip trimming branches in excess of 3 feet in length will encourage lateral growth. This should be done during the winter while the tree is dormant. Mature trees can be trimmed to maintain them at 6-12 feet in height for ease of harvest.
Each year, it’s also good to examine the tree closely and make sure there are not any inward-growing branches. Selective pruning at the crotch of the branch to remove a couple inward-growing branches will improve airflow and light to the rest of the canopy.
Propagation
Propagation of these trees is typically one of two methods: from seed, or from grafting. Other methods are rarely effective.
Grafting a carambola branch onto another rootstock is a common technique used to generate nursery stock. However, it’s not an easy process, and is likely best left to the professionals.
Harvesting and Storing
The only thing better than growing the Carambola plant is enjoying the harvest! Here’s how to harvest and store the delicious, tangy fruits.
Harvesting
Star fruit does not ripen once it’s harvested. When the grooves in the sides of the fruit are completely yellow, and only the very upper tips of the raised sections are still green, it’s time to start harvesting. You can wait for the upper tips to turn yellow as well, but it won’t have as long of a storage life if you do.
Storing
Your harvested star fruits can be stored in a sealed plastic bag in the refrigerator for up to 21 days. Most starfruit is consumed fresh, rather than stored for longer periods of time.
For longer-term storage, puree the star fruit and freeze it in an ice cube tray. You can also dry starfruit using a food dehydrator. The puree can also be used to make jams or jellies. Remove the seeds while processing it for storage.
Troubleshooting
Let’s discuss problems you might face with your home-grown star fruit plants as you care for them. There aren’t a lot of them, but they do exist!
Growing Problems
Soil above a pH level of 7 can cause your home-grown carambola tree to suffer from nutrient deficiencies. An iron deficiency can cause yellowed leaves with green veins or smaller-sized leaves. Manganese deficiencies cause reduced leaf size and yellowing of leaves. Magnesium deficiencies produce mottled yellow and green leaves. Treat with the appropriate micronutrient if these appear.
In addition, while mature trees can handle cold temperatures for short periods of time, it comes with varying stages of potential damage. At temperatures below 60 degrees Fahrenheit, carambola fruit production stops. At temperatures of 30-32 degrees, young leaves can die off. Young trees, mature leaves and young branches can be killed at temperatures between 25-29 degrees. Temperatures 24 degrees and below can kill mature trees.
Pests
Three different types of scale insects are common pests for carambola. Plumose scales (Morganella longispina) and philaphedra scales (Philephedra tuberculosa) attack leaves and twigs. Brown scales (Coccus hesperidum) attack the fruit directly. Regular spraying of horticultural oil will reduce the appearance of these.
Two types of weevils stop by, too. The diaprepes weevil (Diaprepes abbreviatus) causes damage to roots and can cause root and shoot dieback. A fruit weevil called Myctides imberbis can also appear intermittently, consuming the delicious starfruit. These are both treatable with pyrethrin.
Stink bugs and squash bugs both can create small holes in the fruit that can then allow in fungal or bacterial pathogens, causing the fruit to rot. Insecticidal soap is effective against stink bugs. For squash bugs, pyrethrin is a better bet, and it’s effective against stink bugs as well.
At least one kind of thrips, red-banded thrips, attack the flowers and fruit as well. Treat with insecticidal soap, neem oil, or horticultural oil to deal with these pests.
Diseases
An assortment of fungal leaf spot diseases are common on star fruit. Cercospora averrhoa, Corynespora cassiicola, Gloesporium sp., Phomopsis sp., and Phyllosticta sp. are all fungal pathogens that cause these. While typically not very dangerous to your tree, they do provide the warning that your tree is suffering some sort of stress. This could be nutritional deficiencies or stress due to the climate. No control is necessary, only determining the cause of the stress and easing it.
Algal rust is caused by Cephaleuros virescens. This form of rust causes rough grey or red circular patches on the bark and can result in twig dieback. If you believe your tree is experiencing algal rust, contact your local agricultural extension to confirm and to provide information on treatment options.
Anthracnose fruit rot is not uncommon, but you’ll usually see anthracnose leaf spotting first. Treatment of the leaves should prevent the spread to the fruit and to prevent a risk to your tree’s fruit production. To treat, use either a biofungicide that contains Bacillus subtilis, or use a copper fungicide spray. Once fruit is infected, dispose of the damaged fruit.
Finally, root rot caused by Pythium fungi can occur in overly-wet soil conditions. Make sure the soil around your tree readily drains off excess moisture. Some soil mycorrhizae are showing signs of helping protect plants against fungal root rot, but there is no cure once the star fruit tree is already infected, so prevention is essential.
Frequently Asked Questions
Q: How long does it take for a star fruit tree to bear fruit?
A: In the first year, star fruit trees typically don’t produce much if any fruit. After you care for it through its first year, you can expect fruit in either year 2 or 3. Home-grown star fruit trees that are protected from high wind can often be harvested within 10-14 months of planting provided that they’re 2 years or older.
Q: Are star fruit seeds poisonous?
A: Yes and no. For people who have kidney disease, star fruit is generally not recommended at all, as it contains high amounts of oxalic acid. If you are healthy, the seeds or fruit should not harm you.
FAQs
What made the star fruit tree special? ›
Starfruit trees (Averrhoa carambola) are very attractive, with curving branches and large masses of lilac-purple blossoms that attract pollinators. They are grown for their ornamental value as well as their star-shaped fruits.
What is the legend of the starfruit tree? ›'The starfruit tree') is a Vietnamese folktale. It tells the story of a poor farmer who is paid handsomely by a magical bird after letting it feeds on his starfruit tree and his rich older brother who perishes from his own greediness.
How long does it take for a star fruit tree to produce fruit? ›After you care for it through its first year, you can expect fruit in either year 2 or 3. Home-grown star fruit trees that are protected from high wind can often be harvested within 10-14 months of planting provided that they're 2 years or older.
Is star fruit a tropical fruit? ›Star fruit, also known as carambola, is a juicy tropical fruit native to India and Southeast Asia, where it is very popular and heavily cultivated. The yellow, star-shaped fruit grows best in sunny, humid climates and can be found on trees in India, Asia, South America, Australia and in limited areas of the US.
What are the pros and cons with starfruit? ›Star fruit is a delicious fruit. It is low in calories but packed with vitamin C, fiber, and antioxidants. However, people with kidney problems or those who take prescription drugs should consult with a doctor before eating this fruit. For most people, though, star fruit is a healthy and tasty addition to the diet.
What is the danger eating starfruit? ›The substances found in starfruit can affect the brain and cause neurological disorders. This toxic substance is called a neurotoxin. People with healthy, normal kidneys can process and pass this toxin out from their body. However, for those with kidney disease, this is not possible.
What is the symbolic meaning of starfruit? ›This fruit is a symbol of spirituality in Javanese culture. It's five-point star shape symbolizes the five points in spirituality and is called the pancasila (panca meaning five and sila meaning attitude).
Why are starfruit expensive? ›Due to its lack of cultivation and popularity in the U.S., star fruit is more expensive than more common fruits like apples.
Can star fruit grow in pots? ›Growing Star Fruit Indoors
To flourish indoors, potted star fruits need well-drained, loamy soil (Fafard® Natural & Organic Potting Mix) with a slightly acid pH (5.5-6.5) and regular fertilizer for acid-loving fruit trees. Provide them with lots of sunshine and enough water to keep the pots just moist.
Star Fruit, or Averrhoa carambola. is a tropical fruiting tree in the oxalis family that's native to tropical Asia. Widely grown throughout the warmer areas of the world, it has little hardiness but can tolerate a light frost and temperatures into the high 20's for short periods.
What is the best fertilizer for star fruit? ›
2. Fertilize young star fruit trees with 1/2 pound of mixed fertilizer, with a 6-6-6-3 formulation, every 60 to 90 days until established.
Can you eat a starfruit raw? ›Yes, you can eat star fruit raw. The skin is edible and the flesh has a mild, sour flavor that makes it popular in several dishes. Do you peel star fruit before eating? The entire star fruit is edible so you do not need to peel it or deseed it before eating.
What is a fun fact about star fruit? ›Did you know that one star fruit tree can produce between 200-400 pounds of fruit each year? The star fruit, also known as the carambola, is a beautiful funky-looking fruit. With its brightly yellow colored ridges, the fruit resembles a star shape.
How long does it take for star fruit to flower? ›Star Fruit has a long harvesting time and the fruit emerges from June.
Is Starfruit an anti inflammatory? ›The high levels of antioxidants in this fruit make it a good anti-inflammatory that can help ease symptoms of psoriasis and dermatitis. Weight loss promotion. High fiber in star fruit can help also boost your metabolism and allow you to lose weight.
Is star fruit a Superfood? ›Star fruit is considered a superfood now, and is a part of many a health conscious salad-eater's diet. It is full of vitamin C and is believed to help control blood sugar.
Is star fruit anti inflammatory? ›Star fruits are considered to have a number of beneficial health effects. These include antioxidant, hypoglycemic, hypotensive, hypocholesterolemic, anti‐inflammatory, anti‐infective, antitumor, and immune‐boosting effects (Figure 2).
What are the forbidden fruit trees? ›Because the Hebrew Bible describes the forbidden fruit only as peri, the term for general fruit, no one knows. It could be a fruit that doesn't exist anymore. Historians have speculated it may have been any one of these fruits: pomegranate, mango, fig, grape, etrog or citron, carob, pear, quince or mushroom.
What tree has the forbidden fruit? ›They lived in paradise in total innocence until the serpent (the devil) enticed them to eat the forbidden fruit from the tree of knowledge. As punishment for their disobedience, God banished them from Paradise.
What is the most forgotten fruit? ›In 1916, agricultural experts voted the pawpaw the American fruit most likely to succeed, ahead of blueberries and cranberries. But today, most people have never even heard of it, let alone tried it.
Why do I feel nauseous after eating starfruit? ›
Symptoms of “star fruit intoxication” include persistent hiccups, nausea, vomiting, agitation, insomnia, mental confusion and convulsions that occur within one to five hours of eating the fruit. The problem seems to be the high levels of oxalic acid (or oxalate) in this fruit that can accumulate in weakened kidneys.
Why is star fruit poisonous to dogs? ›In some cases, star fruit can prove lethal to dogs as it may result in kidney failure. Star fruit contains oxalate salts, which when absorbed into your dog's gastrointestinal tract, bind with the body's calcium in your dog's system and dramatically and quickly reduce the amount of calcium present in your dog's body.
How toxic is starfruit to dogs? ›While star fruit can function as human food, it is not safe for dogs under any circumstances. Star fruit contains soluble calcium oxalate crystals, which cause calcification and inflammation of the kidney. This can lead to kidney failure and death.
What devil fruit is a star? ›The Hoshi Hoshi no Mi (lit. Star Star Fruit) is a Devil Fruit that grants the user powers related to stars. It was eaten by Fey Serenity, the Musician of the Outlaw Pirates.
Does special star fruit affect everyone? ›How many players does the Special Star Fruit card effect? Special Star Fruit works on all players, not just the one who plays it.
Is star fruit good for your hair? ›Healthy Hair and Skin
The rich presence of antioxidants along with vitamin B and C in starfruit aids healing of skin and hair cells which in turn leads to shining hair and glowing skin. More particularly antioxidants like gallic acid and quercet in display immense anti-inflammatory and antihistamine properties.
Star fruit is a rich source of oxalates. Nephrotoxicity leading to AKI is a result of both tubular obstruction by calcium oxalate crystals as well as apoptosis of the renal tubular epithelial cells [7].
Is star fruit good for diabetes? ›Star fruit (Averrhoa carambola) is a popular fruit in Asian tropics. It is valued for its medicinal and nutritional properties [1]. Its hypoglycaemic effects are considered to be particularly beneficial in patients with diabetes mellitus, and it has been promoted as a traditional remedy for diabetes [2].
Can you eat every part of a star fruit? ›The entire fruit is edible, waxy skin and all -- you just might need to eat around a seed or two. When ripe, the starfruit should be evenly yellow or yellow-green with no traces of green at the tip of the ridges.
How long do starfruit trees live? ›The Carambola tree has a lifespan of 40 years and reaches a height of 7–10 m (22–33 ft), spreading 6–7.6 m (20–25 ft) in diameter. Carambola may also be referred to as averrhoa, starfruit, five corner or coromandel gooseberry and originates from Southeast Asia.
Do you need two star fruit trees? ›
Starfruit trees are self-fertile, but you will have a much larger harvest if you have two or more trees. The Starfruit tree has small, lavender-purple flowers, which are pollinated by a variety of bees, resulting in fruit which is harvested in fall.
How cold can starfruit tolerate? ›Temperature: Thrive in subtropical and tropical climates. Zone 10 to 11, but can be grown in zone 9 with protection from frost. Older trees are more tolerant of frost, but growth stops at 55 to 60 degrees and prolonged exposure to temperatures below freezing could kill the tree.
Is starfruit invasive? ›They are grown as ornamentals. Carambola is considered to be at risk of becoming an invasive species in many world regions.
Where is the best place to plant starfruit? ›Plant your star fruit in full sun, away from other trees and buildings, structures, and power lines. Along with warm temperatures, this plant needs well-drained soil, improved fertilization, and protection from the wind. It may also need supplemental irrigation as carambola is not drought-tolerant.
How do you make fruit trees sweeter fruit? ›Overall, there is little you can do to increase the sweetness of the fruit. Fertilize the tree in early February using a general-purpose fertilizer or citrus tree fertilizer following label directions, but it will likely have little effect on the sugar content of the fruit. (Sugar is manufactured in the leaves.)
What fertilizer make fruit bigger? ›Potassium is the key driver of fruit size and alongside nitrogen is required in large quantities throughout fruit development and growth. However, too much nitrogen at a late growth stage can restrict fruit size; therefore a balanced nutrient application is crucial. Phosphorus can restrict fruit growth too.
What color star fruit is best? ›A perfectly ripe star fruit will have a bright yellow color with tinges of light green. You may also find dark brown along the five ridges. The flesh should feel firm to the touch, though juicy on the inside. You'll know a star fruit is overripe if it turns entirely yellow and starts to have brown spots all over.
Why are star apples important? ›African star apples are a rich source of natural antioxidants such as flavonoids and vitamin E, C, and A. They prevent oxidative damage of cells and promote heart health. Studies have also shown that the African star apple contains glycosides. They are antioxidants that help fight heart disease.
Can you eat starfruit like an apple? ›The entire fruit is edible, though you may want to remove the flat seeds in the center—do this either with the tip of a knife or with your finger. Once cut this way, you can serve this as a fruit alone, in a fruit salad or as a flavorful garnish.
Is star apple good for high blood pressure? ›Star apples are a good source of cardiac glycosides, used in folk medicine as heart tonics. Plant-derived cardiac glycosides can reduce blood pressure by removing salt (sodium) and water from the body. Therefore, star apples may help reduce the risk of heart problems and maintain cardiovascular health (3), (6).