OROBLANCO GRAPEFRUIT

If you are a true grapefruit fancier, you’ll certainly want to become acquainted with the ‘Oroblanco,’ a marvelous fruit that is a cross between a grapefruit and a pummelo and contains not a shudder of bitterness. The Oroblanco is almost as sweet as a navel orange, although it has the characteristic flavor of the grapefruit.

This grapefruit hybrid was developed in the early ‘60s by geneticist Robert Soost at UC Riverside. It is not as popular as it deserves to be because it is not grown commercially to any extent, so only few know about it.

The fruit of the Oroblanco resembles that of a typical yellow grapefruit, but with a slightly paler rind and flesh, the latter not quite as juicy as that of a standard grapefruit. However, the flesh is seedless and tender, and the segments are easy to separate. The Oroblanco makes a delightful breakfast fruit, and, unlike other grapefruit, it is delicious when peeled and eaten like an orange.

The Oroblanco tree is as attractive as the fruit is tasty--a lush evergreen with contrasting yellow fruit and fragrant blossoms.

Although the Oroblanco is said to produce its best-quality fruit in the warmer inland regions, where conditions for growing citrus are generally more favorable, the fruit that we sampled in Chula Vista--a few miles from the ocean but out of the coastal breezes--had a mild, sweet flavor.

The Oroblanco is available only in standard-size trees; being little known, it may be difficult to locate. Ask your local nursery to order an Oroblanco tree from such wholesale growers as Durling Nursery in Fallbrook or Four Winds Nursery in Fremont.

Near San Diego, Pacific Tree Farms in Chula Vista, (619) 422-2440, has a large supply of Oroblanco trees. Los Angeles area residents can contact the Palos Verdes Begonia Farm in Torrance, (213) 373-2228. They usually stock the tree.

The Oroblanco has cultural requirements similar to other citrus trees. It requires a sunny site and quick-draining soil. After planting, water the new tree moderately two times a week for the first four weeks. Then, if there is no rain, establish a weekly watering routine. Fertilize at the time of planting with slow-release fertilizer tablets or spikes. Each succeeding year, fertilize in early spring and again in late summer with a commercially available citrus fertilizer.

A young or new tree will sunburn if exposed to too much sun, so trunks should be protected with white latex paint. Pruning is not necessary, except to remove dead twigs. A mature tree can grow to a height of 30 feet or more, so provide sufficient space for it to reach its maximum potential.