How To Grow A Star Fruit From Seed

The exotic, tropical starfruit tree (​Averrhoa carambola​) takes its common name from the unusual shape of its fruit. They look like five-pointed stars when sliced.

Starfruit trees can be hard to find in the garden store, but they can be grown from fresh seed taken from a ripe fruit. Seed-grown starfruit trees take longer to bear fruit than grafted ones, and their fruit may not be of the same quality. Still, the ornamental value of their rosy flowers and evergreen foliage makes them worthwhile to grow.

The starfruit tree is a short, attractive, slow-growing tropical tree thought to be native to Malaysia, Indonesia, and southern China. Though extinct in the wild, the tree is grown commercially for its unusual fruit. It usually grows 20 to 30 feet tall with a broad, rounded crown.

Fragrant rose flowers bloom in the leaf axils, giving way to waxy, five-sided yellow fruit. When the fruit is sliced, it has a star shape, giving it its common name. People generally eat the fruits fresh, in fruit salads, or as star-shaped garnishes.

Starfruit can be grown from grafted saplings or from fresh seeds. The former method works faster, producing edible fruit quite quickly, while propagation from seed takes years from planting to first harvest.

If you decide to grow a starfruit from seed, you'll need to act carefully. Do not use grocery-store fruit because these seeds rarely grow. A ripe starfruit contains up to 12 oval seeds but only select seeds with dark brown, glossy seed coats for propagation. And act fast. The seeds lose viability quickly, sometimes overnight, so plant them immediately after removing them from the fruit. If you have waited too long, a 24-hour soak in water may revive them.

You will need to prepare a 2-inch pot with multiple drainage holes for each starfruit seed. Wash the pot in hot, soapy water before using it. Then fill it with well-drained soil or a mixture of 2 parts vermiculite or perlite and 1 part sterile potting soil. Sow one starfruit seed per container.

Position the seed on the surface of the soil. Spread a very thin layer of soil over the seed and then tamp it down lightly to increase contact. The seed should be visible beneath the medium but still covered. Place it somewhere warm where temperatures stay above 70 degrees Fahrenheit. Cover it loosely with plastic wrap.

Check the moisture level in the soil daily and spray it with water if the surface is dry. Do not pour water into the pot. Sprouts should appear in one to two weeks. After three weeks, try with a new seed. If sprouts appear, take off the plastic wrap and transfer the seedling to a sunny windowsill.