San José, Costa Rica, since 1956

Rambutan a Tasty Lychee Relative

The mamón chino or rambutan (Nephelium lappaceum L.) harvest has been in full swing this year in Costa Rica, and it’s another chance for tropical gardeners to stock up on new seeds for planting.

This rare fruit tree, originally from Malaysia, was introduced to the country some 40 years ago by the Ministry of Agriculture and Livestock as a new cash crop for small farmers to diversify their farms, instead of relying only on traditional crops such as coffee or sugarcane. The program was a real success, mainly because this new immigrant to Costa Rica adapted really well to our bioregion.

Rambutan is a relative of the lychee tree, and bears a fruit of equal excellence.

The fruits are easy to recognize with their unusual, soft spines of brilliant red or yellow. Inside the fruit capsule, you’ll find a pearllike pulp that tastes something like a mix between cherry and lemon – according to my taste buds, of course. It’s also my opinion that having a few of these trees around the old tropical homestead makes real good sense.

Rambutan is easy to grow and fast to produce, and suffers from few pest problems.

Leading nurseries stock mamón chino fruit trees in varying sizes and varieties.Kids squeal with delight when the harvest comes around and the trees are drooping with ripe fruits. Just be sure to supervise young children – mamón chino is a choking hazard.

The seeds can be washed and saved or planted in pots or plastic nursery bags with prepared potting soil. It’s best to plant the seed horizontally and very superficially in the soil. Keep the soil well watered during the period before germination and then ease off to once a week.

Before we go any further, it’s best to understand the nature of rambutan trees. In botany, they are classified as dieocious trees, which means they have either male flowers or female flowers. You’ll never know the sex of the tree until it flowers, so it’s best to have two or three trees for cross-pollination. Tico campesinos, however, have a belief that certain fruits can be identified as females.

These seed capsules have a little pepa, or embryonic seed capsule, perched near the stem. Perhaps these types are polyembryonic and can shift from male to female; at any rate, researchers have tried to graft trees and start them from cuttings, but with little success.

The fact remains that it’s best to plant three or more trees to have a successful crop; however, this tree has become so popular around the country as a patio fruit tree that bees often pollinate trees throughout the neighborhood.

If you have a small garden, rambutan may not be an ideal choice, since they reach 15 to 25 meters in height, but for gardeners with large tracts for orchards, these trees can produce a nice extra income during harvest time.

Rambutan flourishes from sea level to 500-600 meters, in tropical, humid regions with well-distributed rainfall. The tree does best in deep clay or sandy loam rich in organic matter, with good drainage.

It’s best to allow plenty of space from other trees when transplanting your new trees to their permanent sites. Eight to 10 meters apart is recommended to keep the trees from becoming entangled and competing for light.

Full-sun sites are preferred, as is protection from strong winds – the branches of rambutan trees are brittle and break easily. Poles are often required to support the branches during the harvest to prevent them from breaking.

Children should be restrained from climbing the trees to harvest, which can end in a broken branch or, worse, a broken bone. Use a pole equipped with a cord-operated cutter for cutting the stems with the fruits attached.

The fruits last longer this way, and it helps to prune the tree. Once the kids understand the trees’ right to grow strong and healthy, as well as how to operate the pole picker, things can go well at harvest time.


Comments are closed.