The Oro Blanco, meaning "white gold" in Spanish, is the product of cross-pollinating a seedy grapefruit variety and an acid-free pomelo variety. Oro Blanco is just as sweet during its early stages of ripening as when its peel turns yellow. The segmented flesh is devoid of any color beyond its pale yellow tones and it lacks acidity, making it far sweeter than other varieties. When ripe, the Oro Blanco has a golden yellow peel with a bitter, thick rind, and pith up to a 1/2 inch deep. Its flesh is tender, juicy, seedless and sweet with a large hollow core.
Oro Blanco trees are hardy, preferring to grow in subtropical and warm climates to hot valleys, although they can tolerate near freezing conditions. They grow vigorously to a large size with a somewhat spreading form. The fruit matures early, but retains its freshness on the tree throughout its peak season. Oro Blanco grapefruits are harvested from winter until early spring.
Generally speaking however, late autumn is when grapefruits are ready to pick. Mature fruit may be left on the tree and, in fact, will sweeten throughout the winter. This method enables you to “store” the fruit for a longer period of time than if you picked it all at once. The downside is that storing on the tree reduces the yield the succeeding year. So, late fall into the winter or early spring is when to harvest grapefruit.