Citrus have been in cultivation for centuries. Most breeding and selection was intentional. Even the strange breeding of orange and lemon for the familiar ‘Meyer’ lemon was deliberate. Grapefruit, Citrus X paradisi, is a peculiar one though. Its parents were unknown when it mysteriously appeared in Barbados in about 1750. It is now known to be a hybrid of orange and pomelo, both exotic.
The original grapefruits were ‘white’ grapefruits, with tart and pale yellowish flesh. ‘Pink’ grapefruits, with milder flavor, and blushed flesh, appeared a century and a half later, in about 1906. Those with rich pink flesh are known as ‘red’ grapefruits. Some mildly flavored modern white grapefruits are hybrids of grapefruit and pomelo. Such breeding makes them 75% pomelo and 25% orange.
Both modern and traditional white grapefruit trees are more vigorous than pink and red grapefruit trees. Dwarf white grapefruit trees grow slowly, but might eventually get more than fifteen feet tall. Standard trees can get as big as shade trees. They are too productive for home gardens. Pink and red grapefruit trees rarely get taller than eight feet. Grapefruit foliage is evergreen and lustrous.