A Houseplant Harvest—Tropical Trees That Really Do Fruit Indoors

When you live on a small tropical island, as I do, you learn quickly—à la Robinson Crusoe—that it pays to be self-sufficient. Recently, I've been collecting and propagating fruiting tropical shrubs and small trees on my four-acre property in Vieques, Puerto Rico, like a man with a mission. My ultimate goal is to supply my own table with a diverse mix of fresh produce year-round, grow enough surplus fruit to be able to vend to local restaurateurs, and establish a modest nursery and display garden.

In my former life as a New Yorker, I used to buy exotic fruits in the city's ethnic food markets and germinate their seeds as houseplants. (This practice was nothing new; indeed, it's a popular hobby, with its own gardening club—the Rare Pit and Plant Council—or, less formally, "The Pits.") Avocados, mangos, litchis, star fruit, sapodillas, tamarinds, carobs, and citrus of all kinds made up my indoor orchard. They were all very decorative as foliage plants, but none flowered and bore fruit in my urban loft.

When I moved to the Caribbean a few years ago, I encountered a vast array of good-looking fruiting plants, some of them familiar to me only from books. Many were endemic to the region. After careful observation—and tasting—I compiled from their ranks a list of species that will make marvelous additions to the indoor-plant pantheon. What's more, with proper care and a little pollinator know-how (see Indoor Pollinating Tips below), you can count on them to really fruit indoors.

Not that you'll be filling Steuben crystal fruit bowls full of windowsill-grown goodies: The indoor harvest from these plants is small and intermittent, and the fruits themselves are not that large. But this doesn't mean you'll be reduced to inconsequential nibbling. Let your freezer become your new best friend. When the fruit matures, pick and store it in freezer bags until there's enough to work with. Then let your imagination go wild! Purée the fruits as a base for ice creams, sherbets, mousses, and jams. Bake them in pies and tarts. Use them to make stewed compotes and Hungarian fruit soups. The possibilities are endless.

Here are a few of my current favorites to consider growing indoors. At least one species, Surinam cherry, has become invasive in tropical and subtropical areas around the world, but inside it is unlikely to do much harm and can be mighty tasty.

Carissa macrocarpa (Natal plum)

A familiar houseplant and indoor bonsai subject in cool climes, Carissa macrocarpa is indigenous to the coastal region of Natal, South Africa—hence the common name. A vigorous, spreading, woody shrub, it grows up to 18 feet tall, produces handsome, broad, evergreen foliage, and equips its branches with stout Y-shaped spines. Its two-inch-long tubular flowers are white and sweetly fragrant. The oval fruit of the Natal plum can grow up to two inches long and 1¼ inches wide. As it ripens, the skin turns a bright magenta red. The flesh is tender, very juicy, strawberry-colored, and flavored with flecks of milky sap. The small seeds are unobjectionable and are usually eaten. When fully ripe, the protein-rich fruit can be consumed out of hand or made into jellies, syrups, gelatin-based desserts, pies, and tarts.

The Natal plum is generally drought-resistant, but don't allow the soil to dry out too much between waterings. Provide a sunny exposure and give your plant a summer vacation outdoors, if possible. Fertilize it regularly with any all-purpose water-soluble plant food. Cuttings are terribly difficult to root, so starting from seed is the best method of propagation.

Eugenia uniflora (Surinam cherry)

Indigenous to Surinam and French Guiana, the Surinam cherry has become naturalized throughout the Caribbean. It's also a very popular hedging plant in southern Florida. A slender shrub or tree, it grows up to 25 feet tall and produces spreading branches with aromatic foliage. The flowers are white and long-stalked, and look like powder puffs. The thin-skinned, ¾- to 1½-inch-wide fruit has multiple ribs and matures from green to bright red and finally to a dark plum color. Its flesh is tender, very juicy, and tartly sweet to taste. It's also high in vitamin A. There may be one fairly large seed or three smaller ones. The seeds are extremely resinous and should not be eaten. The fruit ripens quickly, often three weeks after flowering. It is generally eaten out of hand or chilled and sprinkled with sugar.

The Surinam cherry prefers a sunny location but is not particularly fussy about potting soil. Let the soil dry out between waterings. Fertilize it regularly during active growth, flowering, and fruiting—usually in late summer.

Malpighia emarginata (Barbados cherry)

Native to the Lesser Antilles from St. Croix to Trinidad, the Barbados cherry is a handsome small tree that grows up to 20 feet tall. It has an erect habit with waxy, oblong, dark green foliage. Its charming, delicate, highly decorative flowers are borne in twos and threes along the stem, and each one possesses five pink or lavender spoon-shaped, fringed petals. The plant produces three-lobed, inch-wide, tangy, bright-red berries that are wonderfully juicy and refreshing. They are also extremely high in vitamin C, second only to the rose hips of Rosa rugosa. Each berry's three small hard seeds may be eaten or removed, depending on personal preference. Commercial plantations of Barbados cherry can be found in Puerto Rico, Hawaii, and Florida. One cultivar of the plant, 'Florida Sweet', was selected in 1956 for its larger-than-usual fruit and applelike, semisweet flavor.

Give the Barbados cherry a sunny southern or southwestern exposure, away from drafts. A fertile, well-drained potting mixture with a pH of 5.5 to 6.5 is ideal. Let the soil dry out slightly between waterings, and do not let the plant sit in a saucer of excess runoff. Employ an acidifying fertilizer during growth and flowering, generally from late winter through late summer. Propagation is usually from half-ripe tip cuttings.

Myrcia floribunda (rumberry, guavaberry)

Indoor Pollinating Tips

In their natural habitat, tropical fruiting plants have their own pollinators. Hummingbirds, bananaquits, butterflies, bees, beetles, ants, moths, and bats all do their job to fertilize flowers that will subsequently develop into fruit. Obviously, we lack this fauna in our urban high-rise apartments and suburban homes. Although all the plants profiled here have perfect flowers (that is, they possess both male and female organs and are self-fertile), they need a little help in the pollination department. Assist fruit set by employing a small camel's hair paintbrush to transfer pollen from the anthers to the stigmatic surface. You don't have to be too precise, simply jiggle the floral parts about a bit with the brush.

The rumberry is native to the Caribbean and southern Mexico. An attractive large shrub or small tree, it can grow up to 50 feet tall outdoors but only gets up to around 6 feet indoors. It sports reddish-brown, exfoliating bark on mature wood and glossy, dark green foliage. The flowers are small, white, powder puff-like, and borne in clusters. The dark red to near black fruit grows about half an inch in diameter and has a highly aromatic but somewhat bitter taste, reminiscent of elderberries. Generally, the fruit is enjoyed out of hand, but it's also used to make preserves for fruit tarts. In the Caribbean, it's a popular ingredient in numerous alcoholic beverages.

The rumberry prefers full sun and a moisture-retentive but well-drained soil. Allow the soil to remain barely moist but not soggy; a terra-cotta pot may help. The plant needs a sunny exposure and is very sensitive to winter drafts.

Pereskia aculeata (Barbados gooseberry)

Named in honor of the French scholar Nicolas-Claude Fabri de Peiresc, the genus Pereskia boasts the unique characteristic of being one of the few cactaceous genera to bear true leaves. Pereskia aculeata, the Barbados gooseberry, is indigenous to the West Indies, the northern coast of South America, and Panama. A clambering shrub that becomes a loosely climbing vine with age, it produces spiny, fleshy stems and elliptical, semideciduous dark green leaves. Panicles of long-lasting, lemon-scented, creamy-white flowers appear in fall. Upon pollination, one- to two-inch-wide oval or pear-shaped yellow to red fruits develop. When fully ripe, the fruits are juicy, tart, and very tasty. Their soft brown seeds are easily eaten. The fruits may be consumed fresh out of hand or stewed. They are very high in Vitamin A and calcium. The leaves and stems can also be cooked and eaten as greens.

The Barbados gooseberry requires full sun. Use a fertile, compost-enhanced but impeccably drained soil. Add plenty of coarse sand to improve drainage, and be sure to use a terra-cotta pot—the plant is very sensitive to overwatering. Feed it during active growth with your favorite water-soluble fertilizer. Propagation is easy from seeds or half-ripe stem cuttings.

Punica granatum var. nana (dwarf pomegranate)

Steeped in history, mythology, folklore, and romance, the pomegranate needs little introduction. Native from Iran to northern India, the small tree has been cultivated since ancient times throughout the Mediterranean regions of Asia, Africa, and Europe. Though the straight species can grow between 20 and 30 feet tall, the dwarf pomegranate, Punica granatum var. nana, reaches around 3 feet—but it can bloom when it's only about a foot tall. It's a wonderful container plant and is frequently used for indoor bonsai. The leaves are evergreen (except under extreme drought conditions), lance-shaped, and leathery in texture. Showy red, white, or pinkish flowers are borne at the ends of new growth. The rounded fruit of the dwarf pomegranate is about two inches wide and red when ripe. It contains transparent sacs of tart, flavorful, reddish pulp surrounding angular, hard seeds. Though these sacs are edible out of hand, I prefer to juice them and use the resulting liquid as a natural colorant for cream cheese and cake frosting, and as a mixer for sparkling water and cocktails. Pomegranates are high in potassium and have fair amounts of vitamin C and phosphorus.

The dwarf pomegranate is easy to cultivate indoors. It requires a semiarid climate, but keep it away from radiators and heating vents—arid is one thing, desiccating is another. Use a good-quality potting soil amended with lime, and plant in a terra-cotta container. Let the soil dry out between waterings, and don't let the pot sit in a saucer of excess runoff. Fertilize it regularly in spring and summer. Dwarf pomegranates are easily propagated from seed and hardwood cuttings.

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