Grapefruit trees (Citrus paradisi) developed as a hybrid result of mixing a sweet orange (Citrus sinensis) and also a pummelo (Citrus maxima) together. The result was an evergreen tropical fruit, which grows in U.S. Department of Agriculture plant hardiness zones 8 through 11. This large-fruiting tree originated in Barbados in which it made its way to Florida and California. At the home garden, the magnitude of the grapefruit tree is a significant consideration prior to planting.
Growth Rates
The average size of a grapefruit tree is around 25 feet tall, but a few trees are known to reach 45 feet tall with age. In perfect growing conditions with rich ground, a young grapefruit tree may grow up to 24 inches per summer, based on the variety. Most trees are thought to be medium growing trees, reaching 20 feet high in 20 decades, averaging only 12 inches of yearly growth.
Dwarf Size
Most grapefruit trees are grafted and the dwarf dimension is decided by the rootstock. Several diverse types of hardy citrus rootstock are utilized for grapefruit trees, however, the flying dragon rootstock creates the true dwarf size of only 4 to 8 feet tall. Normal Damp or semi-dwarf grapefruit trees hit 8 to 12 feet high. One dwarf variety is that the “Dwarf Redblush” grapefruit tree (Citrus paradisi “Dwarf Redblush”), that grows best from the earth in USDA zones 9 through 10. This 8- to 12-foot-tall evergreen creates red grapefruit with only a couple seeds, ripening on the tree from the spring and winter.
Standard Size
Standard grapefruit grows between 18 and 25 feet tall in normal garden conditions. These trees need plenty of room to expand their large canopies. One example is that the “Redblush” grapefruit tree (Citrus paradisi “Redblush”), growing in USDA zones 9 and 10. This fast-growing tree attains 20 to 25 feet tall with a wide round canopy filled with large red-fleshed fruit with red blushes.
California Big Tree
One grapefruit tree in Porterville, CA is registered on the California Big Tree record. Based on Cal Poly Urban Forest Ecosystems Institute, this fruit tree measures 18 feet high with a trunk over 3 feet around. The canopy spreads out to the width of about 29 feet.