How to Grow a Star Fruit Tree: The Latest Planting Techniques and Methods Tutorial

Star fruit, also known as carambola, five-ridge fruit, and yangtao, is an evergreen small tree of the genus Averrhoa in the wood sorrel family Oxalidaceae. Its fruit has very high nutritional value. It is native to Malaysia and Indonesia and is now widely grown throughout the tropics. In China, it is cultivated in Guangdong, Guangxi, Fujian, Taiwan, China, Yunnan and other places. Let us take a look at star fruit tree planting techniques below!

Growth Habits of the Star Fruit Tree

The star fruit tree prefers a hot and humid climate and is not cold tolerant. It is best cultivated in loam with deep soil, loose and fertile texture, and rich in humus. It likes high temperatures and humidity, and fears frost damage and drought. Prolonged drought and dry hot winds cause flower and fruit drop. It likes semi-shade and avoids strong sunlight, especially during the flowering and young fruit stages. It likes gentle breezes and fears typhoons; the fruit stalks are slender and weak, and typhoons cause a large amount of flower and fruit drop. When the temperature is below 15°C, seedlings stop growing; below 10°C they suffer cold damage, affecting flower bud differentiation, fruit development, yield and quality. Above 15°C the branches and shoots begin to grow, and the flowering period requires temperatures above 27°C. It has wide adaptability and can be planted in areas with annual rainfall of 1500-3000 mm. It is not strict about soil requirements and can grow in various soils, but deep, fertile sandy loam is best, with a pH value between 5.5 and 6.5.

Cultivated Varieties of the Star Fruit Tree

1. Malaysian Sweet Star Fruit: The Malaysian sweet star fruit plant is tall, grows quickly, and has a high fruiting rate. The flesh is crisp, fine-textured, and juicy with a sweet taste. The single fruit weighs 200-300 grams. The fruit is oblong with 5 ridges, and the ridges are thick. The edible rate is 96%, the quality is excellent, and it is resistant to storage and transport.

2. American Red Star Fruit: The American red star fruit is similar to the Malaysian star fruit. The tree shape is cylindrical, the leaflets are slightly hard and crisp, the long leaves are pink, and the inflorescence is purplish red. The single fruit weighs 150-250 grams and has excellent fresh-eating quality.

3. Taiwan Misi Star Fruit: Taiwan Misi star fruit can sprout 5-6 times a year. In hot and rainy seasons, the new shoots grow without an intermittent period, showing early fruiting and high yield. The single fruit weighs 150-200 grams, and the flesh is tender, juicy, and refreshingly sweet.

Propagation Methods of the Star Fruit Tree

1. Grafting propagation: Star fruit most commonly uses patch budding, cut grafting, and cleft grafting. Spring (February-May) and autumn (September-October) are the most suitable periods for grafting. Using grafted seedlings for planting maintains the excellent qualities of the mother tree. Apart from extremely cold weather, planting can be done all year round. The planting spacing is 3×4 m or 3×5 m, with 40-50 plants per mu. After the tree canopies meet, thinning can be carried out.

2. Layering propagation: Air layering propagation of star fruit is commonly known as ringing, marcotting, and the Chinese layering method. It is the traditional asexual propagation and seedling-raising method first adopted in China. This method has the characteristics of simple operation, fast seedling formation, early fruiting, and the ability to maintain the excellent traits of the mother tree.

Planting Techniques for the Star Fruit Tree

1. Site selection and orchard establishment: If the star fruit orchard is established on hilly land, it is advisable to choose south-facing or southeast-facing mid-to-lower slopes with a water source for irrigation, relatively good soil quality, and a gentle gradient. For orchards on flat land, it is generally required to dig drainage and irrigation ditches, with the depth determined by the height of the groundwater level, and to gradually repair and improve them year by year.

2. Planting density: The planting spacing for star fruit can use 3×4 m, 3×5 m, or 4×4 m. Before planting, large planting holes should be dug and sufficient decomposed organic fertilizer should be applied as base fertilizer. In flatland orchards, the planting holes should be 50 cm deep and 50 cm wide; for poor soil, they can be appropriately deepened and widened. In hilly orchards, the planting holes should be 1 m deep and 1 m wide. After planting, the holes still need to be expanded and the soil improved year by year.