Star fruit, or carambola, is a unique tropical fruit we can grow here in central Florida. It may not survive very cold winters, but it will come back from the roots if it is killed back (if it is not a grafted tree). Star fruit are native to Southeast Asia, but older varieties have been grown in Florida for over 100 years. The newer cultivars are sweeter than the tart older ones, but they are all tasty in my opinion.
The trees are evergreen, although they may lose a few leaves in our cold during the winter. They can grow to 20-30 feet tall with single or multiple trunks, but regular pruning will keep them at picking height. The flowers are pink to lavender colored, but not that obvious. In 60 to 75 days you should have fruit from the flowers. The fruit are fleshy and yellow with a thin, waxy, delicate skin that does not need to be peeled. Seeds are small and edible. The fruit are crisp and a good source of vitamins C and A, phosphorus, and potassium. Slices of the fruit look like stars, thus the star fruit name. The fruit can be eaten fresh, made into pickles, or frozen into fancy ice cubes among other uses. I like them fresh or pickled topping a salad. Please note that people with kidney disease should not eat the fruit unless their doctor says it is safe because of the high oxalic acid in them.
Watch a video on cooking with carambolas.
Plant your named cultivar or grafted tree in full sun and away from other structures. Warm temperatures, well-drained soil, fertilizer, protection from the wind, and occasional irrigation will make your carambola tree happy. You can tell when your plant needs water because the leaves fold and hang down. Make sure the trunk is protected from weed eater or mower damage with a grass-free area two to five feet out from the trunk. The plant is easy to grow with very few pests. Harvest fruit from June to February as some cultivars produce two to three crops per year. For the sweetest fruit leave the fruit to ripen on the tree until they are nice and yellow with no green ridges. Ones bought in the store are usually harvested a little green, so the ridges of the stars are green, and the fruit is firm, but not nearly as sweet as ones grown in your own yard.
The cultivars ‘Fwang Tung’, ‘Golden Star’ and ‘Arkin’ produce well without cross pollination, while varieties ‘B-10’ and ‘B-17’ produce more fruit when cross pollinated with another variety. Plants should start to produce fruit in 10-14 months after planting and can produce 10-40 lbs per year per tree when 2-3 years old. Mature trees can produce 250-350 lbs per year, so be prepared for large crops. More details on how to grow start fruit.