We are still in the jungles of Borneo, home of orangutans, proboscis monkeys and humans who have lived here for tens of thousands of years. The amazing thing about the forests of Borneo is that there are so many fruits and nuts that are good for human consumption. I can imagine early inhabitants finding edible fruits in the forests and dispersing the seeds by one way or another time and time again.
When the first humans arrived in Hawaii, there wasn’t much in the forests that was edible. They brought with them the coconut palm, mountain apple, breadfruit, banana and kukui. Now because of human activity, we find all kinds of fruit trees growing wild creating a new kind of Hawaiian forest complex in just a few hundred years. To this day, we continue to add to the tropical fruit tree mix by what we plant in our gardens.
If you are looking for an exotic tree that’s just right for a small yard, one that grows easily, takes very little care, and produces fruit, get acquainted with the star fruit. The carambola, also known as the star fruit or Averrhoa carambola, is a tropical Malaysian fruit that should be more widely grown in Hawaii. The tree was introduced into the islands around 100 years ago. It was probably brought from the old world tropics.
One reason we don’t see it more is that variability exists in seedling populations. Fruits of many seedlings are sour, but nurseries are beginning to carry grafted plants rather than seedlings because of the superior fruit.
The star fruit makes a small tree and will only grow to a height of about 20 feet. The habit of growth is such that the tree may be easily trained to various shapes. If not pruned, it develops a rounded, open crown. The tree is wind-resistant, often withstanding hurricane-force winds with little damage.
Carambola trees should be planted in a well-drained location since they are damaged by flooding. It will tolerate dry conditions, but growth and fruiting are reduced by extended periods of drought.
The tree does best at lower elevations since it is of tropical origin. In most areas of the state, it does not thrive above 2,000 feet. Plant young trees in a sunny location. After it is established, look for loads of fruit. Maintenance is easy. Fertilize with a 1-1-1 ratio fertilizer three or four times a year. Fertilizer should be spread under the canopy and extend 2-3 feet beyond.
Insect pests and diseases are usually not a problem. The root system is not aggressive so the tree may be planted near the house, patio or driveway. The fruit produced can be eaten fresh, used in drinks or salads or made into preserves or jellies.
Another interesting fruit is the West Indian Barbados cherry. The Barbados cherry is not a cherry as such but a member of the Malpighia family. It bears the highest known vitamin C content of any fruit. As a comparison, oranges average 49 milligrams of vitamin per 100 grams of edible fruit (100 grams is about 3.5 ounces). The Barbados cherries, picked as they are turning green to red, average more than 4,000 units per 100 grams. The tartly flavored three-lobed fruit may be eaten fresh, or it is super when used in jellies or preserves or is canned.
Seldom growing taller than 12 feet, their small dark green leaves are contrasted by lighter undersides and, for added interest, they usually have curly edges. The white and delicately pink-tone flowers appear singly or in clusters in the leaf axils.
Easy to grow seedlings produce fruit between the first and third year, while grafted trees come into production the first year after planting. Of bing cherry size, the fruit ripens gradually over a period of time. Highly disease resistant, this dual purpose shrub requires only routine garden care.
Those vitamin pills on your shelf, besides being pretty expensive items, are not nearly as palatable and eye appealing as fresh fruit, especially when it is grown in your own backyard. Take vitamin A for instance. One medium mango is supposed to contain 8,380 International Units while 5,000 IUs per day are listed as adequate.
A few other dooryard fruits that are high in this vitamin A are papayas, Japanese persimmons, avocados, bananas, oranges, tangerines, cantaloupe and Surinam cherry.
Some other tropical fruits famous for their contribution of vitamins are grapefruit, guava, mangosteen, soursop, sapote, cherimoya, lychee, longan, breadfruit, jakfruit and passion fruit. If you have the taste for it, the durian is becoming available at some nurseries. This rather “aromatic” fruit may be found at local farmers markets selling for $15 or more.
For sources of these and other tropical fruits, contact your local nursery.
This information is supplied by the University of Hawaii College of Tropical Agriculture and Human Resources. For further information, contact the office near you to speak to one of our knowledgeable Master Gardeners.