The tree tomato (also called tomato tree) is a popular name for the Tamarillo (Cyphomandra betacea), a subtropical fruiting shrub or small tree with origins in the South American Andes Mountains. Not a true tomato, the Tamarillo is related to the Tomatillo, a familiar ingredient in Mexican cuisine. Tamarillo is the designated name for the plant in New Zealand, where it is grown commercially.
The tree tomato, an evergreen with shallow roots and brittle wood, grows from 10 to 18 feet high. A wind gust can blow it over and break its limbs. In the Andes, it thrives in elevations between 5,000 and 10,000 feet high. It likes temperatures above 50 degrees Fahrenheit. Frost will kill foliage, small branches, seedlings and cuttings, but mature tree will recover if the frost is not prolonged or repeated. It can be grown as a houseplant and in northern greenhouses.
Leaves and Flowers
The heart-shaped leaves are thin with conspicuous veins. They are from 4 to 13 ½ inches long and 1 ½ to 4 ¾ inches wide, alternate on the branch and have a musky smell. They are easily damaged by strong winds.
The ½-to-¾-inch flowers, usually borne in the late summer or early fall, have five pointed lobes that are pale pink or lavender with yellow stamens and green or purple calyx. They hang in small, loose clusters near the tips of the branches and are self-pollinating.
The fruit comes in several colors including yellow, orange, blood red, deep purple, or red and yellow. They’re from 2 to 4 inches long and 1 ½ to 2 inches wide and are borne individually or in clusters of three to 12. They sometimes have faint, dark stripes running from end to end.
The somewhat tough and unpleasant-tasting skin surrounds a firm, juicy but bland-tasting outer layer and an soft, juicy center that is both sweet and tart. The yellow varieties are usually sweeter.
The inner pulp is black in fruits that are red or dark purple; it is yellow in orange and yellow fruits. The seeds are nearly flat, thin, and circular. Pick Tree tomatoes when they have achieved the color of their variety. You can store them for up to 10 weeks in a refrigerator. The juice can leave an indelible stain on a permeable surface.
Tree tomatoes can be grown from seeds or cuttings.
Seeds yield erect trees with high branches; cuttings result in short, bushy plants with lower branches. For truer results, use seed from yellow fruits with yellow seed pulp or from red fruits with black seed pulp. Freeze the washed and dried seed for a day before planting.
For cuttings, use one to two-year-old wood from 18 to 30 inches long. Remove the leaves, cut a square base beneath a node, and plant. Don’t let it fruit the first year.
Tree tomatoes need a light, rich, well-drained soil. They need full sun and protection from strong winds. Mulching will help the tree tomato survive prolonged periods without water. Move trees to partial shade in hot dry weather.
Apply ½ to 2 pounds of 5-6-6 fertilizer for each tree, half in early spring, half in mid-summer and a half-pound of superphosphate every other winter. Prune newly-planted tree tomatoes three to four feet to encourage branching. Fruit is produced on new growth; to induce new shoots and get a better harvest, annually prune branches that have already fruited.
Planting next to a building or wall can help protect tree tomatoes from frost as will covering them with plastic. Tree tomatoes can be attacked by fruit flies and green aphids. They are subject to infection by powdery mildew, cucumber mosaic virus and potato virus.