Last week, we traveled vicariously to visit the tropical fruits of the New World. This week, let us imagine that we are in the jungles of Borneo, home of orangutans, proboscis monkeys and humans who have lived there for tens of thousands of years.
The amazing thing about the forests of Borneo and tropical Asia is that there are so many fruits and nuts that are good for human consumption that it would be difficult to go hungry. The reason is that primates, including humans, ate and distributed what they liked to eat. Think about it. When we are walking along a road and we find a delicious mango, we toss the seed, and up comes anther mango tree. We 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 were very few edible forest fruits. 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 unique 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 in 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 about 20 feet. The habit of growth is such that the tree may be easily trained to various shapes. If left unpruned, it develops a rounded, open crown. The tree is wind-resistant, often withstanding winds of hurricane force with little damage.
Carambola trees should be planted in locations with well-drained soil, 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 the young tree 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 to 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.
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-size mango is supposed to contain 8,380 IU (International Units) while 5,000 IU per day are listed as adequate.
A few other dooryard fruits that are high in this vitamin A are Japanese persimmons, bananas, oranges, tangerines and other citrus fruits. Some other Asian tropical fruits famous for their contribution of vitamins are citrus varieties, mango, mangosteen, lychee, longan, breadfruit, breadnut and jackfruit. If you want to get the most bang for your buck, the jackfruit is a natural. It is almost pest-free and will produce fruit that weigh up to 80 pounds in just a few years after planting from seed.
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. Both the Jackfruit and the Durian are easily grown from seed. The secret is to plant the seed fresh from the fruit, because they lose viability very quickly.
If you live in one of the very hot and dry parts of the island like South Kohala, you might consider fruit trees like the date palm, pomegranate and fig. Originally from the Middle East, these produce the best quality fruit where conditions are similar to desert regions of North Africa and the Eastern Mediterranean. You might even try nuts like the almond and pistachio.
For sources of these and other tropical fruits, contact local nurseries and our University of Hawaii master gardeners. In Kona the number is 322-4893, and in Hilo, call 981-5199.