Mix together well. Fertilizing. Fertilize young starfruit with 10-10-10 fertilizer every month, except in winter. Phosphate also helps to encourage blossom and fruit development once fruit trees mature. This tree does not grow well in soggy or flooded soil. Source: beautifulcataya. You may be familiar with starfruit (Averrhoa carambola).The fruit from this subtropical tree has not only a delicious tangy flavor reminiscent of an apple, grape, and citrus combination, but is truly star shaped and, thus, unique among its exotic tropical fruit brethren. Water and Fertilizer. The Carambola, also called Star Fruit, is a small to medium sized tree that produces a juicy tropical fruit. Ideally a fertilizer with an N-P-K ratio of about 2-1-1 or 3-1-1 … Potassium (the last number) helps to regulate metabolism and other processes within the tree. 1 pound: 21-0-0 (High Nitrogen Fertilizer) 1 cup: Soil Sulfur. Fertilize roughly every 3-4 months. Mature trees should be fertilized 4-6 times per year, and young trees every 30-60 days throughout the growing season. In the tropics, starfruit trees can be planted year round but in colder regions, plant Carambola in the summer. As the star fruit is growing, its color blends in among the leaves. 1/3 cup: Epsom Salts Plus. Additionally, you can apply compost or manure to improve the soil texture. Starfruit tree care, as you may have guessed, requires warm temperatures. Grass growing beneath the trees may take up much of the fertilizer, and heavy rains may send dissolved nitrogen into streams or drainage ditches, where it becomes a pollutant. These trees are propagated via seed or by grafting.That said, seed from this particular fruit is only viable for a short period of time, mere days at most, so use the freshest seeds available to increase the chances of germination. However, fruit flies and scales may attack it. For older, established trees, you can also use a half-strength fertilizer in the fall. How to Plant a Starfruit Tree. Fruit trees typically have different nutritional needs than other types of trees, so most of the time, fruit tree fertilizer will have a completely different chemical makeup than other tree fertilizers. This is right before the growing season and the perfect time to provide the extra nutrients that the plant needs to be prepared. The flavor combines those of the apple, grape and citrus and is crisp in texture. 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. THE “STAR POTION” FOR FRUIT TREES. Carambola trees are moderately-high feeders. 2. The best time to fertilize fruit trees is in the late winter or early spring. Planting & Care Tips for Your Star Fruit (Carambola) Tree June 14, 2011. Use according to the following directions: For Trees planted one full year— use 1/2 cup per tree. Pests and Diseases. Slow release fertilizers work well. Mature trees should be fertilized at the beginning of the growing season. 1/2 cup: Superphosphate. Starfruit is somewhat a pest-free tree. For Trees planted two years—use 1 cup per tree. Apply the fertilizer around the tree and not simply next to the trunk as most of the roots will grow farther away from the trunk. 1/2 cup: Cottonseed Meal. A leading fruit tree nursery in the US recommends using a high nitrogen fertilizer applied to the soil’s surface around trees, but this method has drawbacks. Moist soil is necessary for a star fruit tree, especially during its fruit development. The fruit can be eaten fresh and is often used in salads and as a garnish due to its unique star shape.