Culture
Winter hardy to USDA Zones 9-11 where this citrus tree grows well in sandy, well-drained soils in full sun to light shade. Best performance occurs in full sun. Provide consistent and regular watering. Avoid wet poorly drained soils. Trees will tolerate temperatures that occasionally drop to 32 degrees F. , but will not survive temperatures to 26°F. Plants prefer warm tropical to sub tropical climates with abundant rainfall. Pummelo is being successfully grown in the U.S. in protected locations as far north as USDA Zone 8b. Species plants may be propagated by seed, but named cultivars should be propagated by grafting.
Noteworthy Characteristics
Citrus maxima, commonly called pummelo, is a parent of the grapefruit (C. sinensis x C. maxima). It is probably native to Thailand, but some experts say Polynesia and the Malay Peninsula. Today it is a very popular fruit in Southeast Asia and China. Some limited commercial growth takes place in the U.S. today (Florida, California and Hawaii). The fruit of this tree is huge, typically growing to 6-9" (less frequently to 12") in diameter. Weight is typically 2-4 pounds, but infrequently can mushroom to as much as 15 pounds. Fruits are pear-shaped with a thick rind. Taste of the fruit is reminiscent of grapefruit, but sweet instead of sour with less juice. Edible flesh is white, yellow or pink. Pummelo typically grows to 15-20' tall with a rounded crown. In optimum growing conditions it may rise to as much as 50' tall. Ovate to elliptic leaves (4-8" long) are evergreen. Solitary or clustered white flowers (each to 1 1/3" long) may bloom up to four times per year in ideal conditions, resulting in fruit being present on the tree almost year round.
Sweetener known as bitter narjin (used in TANG breakfast drink) comes from pummelo.
The genus name Citrus is from classical Latin.
Specific epithet means largest
Problems
No serious insect or disease problems.
Uses
Popular edible fruit in southeast Asia. Grown primarily as an ornamental in Florida and California. Useful as a shade tree, background planting, and/or landscape accent. The fruits are reportedly the largest citrus fruits in the world, and a small tree covered with fruit is an attention getter even if the fruits are never consumed.