Grapefruit apparently originated as a natural mutation of the shaddock or pummelo somewhere in the West Indies. It was first described in 1750 in Barbados, while the first record of the term grapefruit occurred in 1814 in Jamaica. Credit for its introduction to the United States in accorded to Count Odette Phillipe, a Spanish don, who planted it in Pinellas County, FL, about 1823. That grapefruit originated as mutation from pummelo seems more likely when one considers the number of grapefruit varieties today, most of which originated as mutations from existing grapefruit varieties.

While Charles Volz is credited with the first successful orange plantings on sour orange rootstock in the Lower Rio Grande Valley of Texas in 1908, little is known of the first plantings of grapefruit in Texas. The earliest record of grapefruit shipments from Texas was 120 tons during the 1919-20 season. Texas grapefruit production peaked at 960,000 tons during the 1945-46 season, which coincided with a peak U.S. production of 2,485,000 tons. That total U.S. production was not achieved again until 1971-72, but Texas grapefruit production has rarely exceeded half its peak level.

While the first grapefruit were white-fleshed and seedy, the Texas grapefruit industry ultimately developed around seedless, red-fleshed varieties, all of which arose in Texas by mutation from existing grapefruit.

Except during major freezes and the recovery from them, the Texas citrus industry annually produces more tonnage, about 80 percent of which is grapefruit, than all other tree fruits and nuts in Texas combined. Because of this and the quality and importance of Texas red seedless grapefruit, the Legislature in 1993 designated red grapefruit as the State Fruit of Texas.

CLIMATE

Grapefruit achieves its best quality under conditions of hot days and warm to hot nights, which results in higher sugars and lower acids than grapefruit produced in the cooler night temperatures common in Arizona and California. It grows well in both tropical and subtropical climates of the world, but it is a little less cold hardy than oranges.

Mature, healthy grapefruit trees that are well-hardened by previous cool to cold weather can probably tolerate temperatures in the mid-20's without leaf or twig damage, although ice will form in the fruit of grapefruit after about 3 to 5 hours at 27. Because severe freezes kill grapefruit trees in the Lower Rio Grande Valley, successful home grapefruit production will sooner or later require cold protection measures.

SOILS AND SITE SELECTION

Grapefruit trees on sour orange rootstock are well-adapted to deep, well-drained soils. Loamy soils are preferred while heavy clays and poorly-drained soils will result in poor growth and production as well as shorter life.

For maximum cold protection, grapefruit in the home landscape should be planted on the south or southeast side of the house. Distance from the house or other buildings and driveways or walkways should be at least 12 feet to allow adequate room for the tree to grow to its mature size. While large, overhanging shade trees will provide some cold protection, grapefruit grows and produces best in full sun.

VARIETIES

The major grapefruit varieties in Texas are 'Ruby Red', 'Henderson'/'Ray' and 'Rio Red'. All were discovered in Texas and all are red-fleshed, seedless and have varying degrees of redness in the peel.

'Ruby Red' was discovered as a limb sport ( a mutation of one limb which has different fruit characteristics than the rest of the tree) on a 'Pink Marsh' tree in 1929 by A. E. Henninger of McAllen, TX, who was granted a patent (U.S. Plant Patent No. 63) in 1934. The fruit is of excellent quality, seedless (i.e., 0 to 6 seeds), red-fleshed, oblate and thin skinned. The fruit usually has a red blush on an otherwise yellow peel. The interior color fades badly after the first of the year.

At least half a dozen other limb sports of 'Pink Marsh' were discovered in Texas between 1930 and 1940--all very similar to 'Ruby Red'--plus one limb sport from 'Foster' pink seedless grapefruit. For the most part, all are lumped together as 'Ruby Red' for commercial purposes.

'Henderson' and 'Ray' are usually lumped together in the industry as they are nearly indistinguishable. Both were discovered in the Valley in the early 1970's-- 'Henderson' as a limb sport on 'Ruby Red' and 'Ray' as four trees, the buds of which were supposed to be 'Ruby Red'. The fruit of these two varieties is similar to 'Ruby Red' in almost all respects except that the peel is more attractive than 'Ruby Red' and the flesh is even redder. While the flesh color also fades after mid-season, it retains some semblance of redness far longer than is the case with 'Ruby Red'. Three other similar limb sports of 'Ruby Red' were discovered in the 1970's by Texas growers, but none has achieved the prominence of 'Henderson'.

'Rio Red' was discovered in 1976 by R. A. Hensz as a limb sport on a tree being grown from 'Ruby Red' budwood that had been irradiated. Released in 1984, 'Rio Red' has interior color that is twice as red as 'Henderson' and its color persists throughout the season. 'Rio Red' has an overall reddish tinge on the peel and a lighter-colored halo in the flesh when viewed in cross-section. The biggest detriment of 'Rio Red' is that its basic shape is more spherical than oblate and sheepnosing of the stem end is a persistent problem.

Texas markets its 'Ruby Red' and 'Henderson'/'Ray' under the name Ruby-Sweet. Some 'Henderson' fruit are marketed as 'Flame' to distinguish it from 'Ruby Red' and to capitalize on Florida's 'Flame' grapefruit which is a nucellar 'Henderson' . 'Rio Red' is marketed under the name Rio Star.