Culture
Winter hardy to USDA Zones 10-12. This plant is intolerant of frost. It is best grown in tropical or semi-tropical climates in rich, humusy, consistently moist but well-drained organic loams in full sun. Best fruit develops in full sun. Plants tolerate light shade if grown ornamentally instead of for fruit. In St. Louis, plants may be grown in large tubs that should be overwintered indoors in bright locations. Container plants may need to be replaced every 4-5 years. Papayas can be heavy feeders, so regular fertilization is necessary.
Noteworthy Characteristics
Carica papaya, commonly called papaya, is a small, frost-tender, succulent, broadleaf evergreen tree that bears papaya fruits throughout the year. Each tree (Hortus Third asserts papaya is technically a giant herb because it never produces true woody tissue) typically has a single, unbranched, non-woody trunk bearing the scars of old leaf bases. The trunk is topped by an umbrella-like canopy of palmately lobed leaves. Large, fleshy, melon-like fruits (papayas) hang in clusters attached to the trunk top just under the leaf canopy. Papaya typically grows to 6-20' tall (container plants to 10' tall) and is most noted for its edible melon-like fruit. It is native to lowland tropical areas of Central and South America, but is now grown in tropical to subtropical regions throughout the world both commercially and in home gardens. In the U.S., it is commercially grown in southern Florida, southern California and Hawaii. Seven lobed leaves (to 2' wide) on leaf stalks to 2-3' long are ornamentally attractive. Species plants are typically dioecious (separate male and female trees), but cultivars are hermaphroditic. Fragrant, trumpet-shaped, yellowish-white flowers bloom throughout the year, with males in long racemes and females in small clusters or solitary. Female flowers give way to smooth-skinned green fruits that ripen to yellow-orange with a yellow to pinkish-orange flesh and central cavity of pea-sized black seeds. Fruits and seeds are edible. Commercially sold fruits are typically 6-8" long and weigh about one pound, but fruits in the wild in ideal growing conditions can grow much larger with a wieght of up to 20 pounds. Papain (an enzyme extracted from the milky sap of green fruit) is popularly used as a meat tenderizer, chewing gum additive and beer clarifier plus for a large number of additional medical, cosmetic and industrial purposes.
Genus name comes from Greek meaning a kind of fig in reference to the fig-shaped leaves.
Problems
No serious insect or disease problems. Root rots may occur in overly moist soils.
Uses
Grown for fruit production. Trees are short-lived, but have some ornamental value as large-leaved tropical plants.