A tomato tree, more precisely called a tree tomato, is a different species of plant than the one that grows the vegetable from a vine in the garden. This perennial shrub stands between 6 and 10 feet high and possesses large, heart-shaped hairy leaves that typically grow to about 5 inches in length.
The plant is widely cultivated in South America and warmer, northern climates like that found in Florida. The tree tomato, Cyphomandra betacea, bears more resemblance to an eggplant than a tomato. The fruit of the tree grows to between 2 and 3 inches in length, with a smooth, oval body attached to a long stem, and blooms about two years after first seeding. Upon blooming, approximately three months are required before the tree tomato bears fruit. The plant is also known as a tamarillo, a name adopted by New Zealand farmers in 1970 and now used widely.
The fruit possesses a taste similar to an under-ripe or very mild tomato and holds a tough outer skin. Fruit production from the tree declines drastically as it reaches 6 to 7 years of age, and the tree tomato is unable to overwinter anywhere that the temperature falls below freezing. The fruit is typically used commercially in stews or preserves. According to the University of Illinois Extension service, some tomato varieties -- like Ponderosa -- that are acceptable for pruning and training, are often sold in stores as tree tomatoes.
There are no named cultivars, but the fruit comes in a variety of colors including red, dark red -- called "black" commercially -- purple and yellow. The premier taste is generally considered to reside in the yellow variety.
The tree tomato requires fertile, light soil, completely disdaining earth that is compacted. It does not tolerate areas with poor drainage, as standing water -- even for just a few days -- routinely kills the plant. It thrives when the temperature remains above 50 degrees F, although it can tolerate some frost to as low as 28 degrees F. A mature tree can recover if such frosts are infrequent, but young seedlings and cuttings will die in these conditions.