It may look like a tree, but papaya (Carica papaya) is actually a big perennial with a hollow stem. Native to the lowland regions of the tropical Americas, it forms an erect, unbranched trunk 620 ft. tall, with a palmlike, 3- to 6-ft.-wide head of foliage. Leafstalks about 2 ft. long carry deeply lobed leaves to 2 ft. across. Plants flower and fruit simultaneously throughout the year. Plants can either be male, female, or hermaphroditic. Only female and hermaphroditic plants will set viable fruit, so plant several seeds and discard the male plants. Male flowers are yellowish and held on stalks; female flowers are larger, white or cream colored, and sprout directly from the trunk. Plants usually begin blooming 6 to 12 months after germination.
Two types of papaya are grown in the SouthHawaiian and Mexican. Hawaiian types (the kinds found in grocery stores) bear oblong, pear-shaped, or rounded fruit that typically weighs 1 to 2 pounds and has orange, red, or pinkish flesh. The fruit of Mexican types weighs up to 10 pounds and has yellow, orange, or pink flesh. Though you can pick papayas slightly green and let them ripen at room temperature (do not chill unripe fruit), they'll have the sweetest flavor if allowed to ripen on the tree. Harvest when the fruit feels slightly soft and its skin is almost completely yellow. Avoid touching the stem's milky sap, which can cause dermatitis. Selections include these eight.
'Mexican Yellow'. Mexican type. Yellow-fleshed fruit up to 10 pounds.
'Rainbow'. Hawaiian. Pear-shaped, 1- to 2-pound fruit is similar to 'Solo'. Genetically modified to resist ringspot.
'Solo'. Hawaiian type. Pear-shaped to rounded fruit has reddish orange flesh, weighs 1 to 2 pounds. Plant may be either female or hermaphroditic.
'Sunrise'. Hawaiian type. Pear-shaped, 1- to 2-pound fruit with reddish orange flesh. Bears fruit when only 3 ft. tall.
'Tainung No. 1'. Hawaiian type developed in Taiwan. Roundish, red-fleshed fruit weighs about 2 pounds. Good keeper. Tolerates ringspot.
'Tainung No. 2'. Hawaiian type developed in Taiwan. More productive than 'Tainung No. 1'; fruit is similar but slightly smaller and has reddish orange flesh. Tolerates ringspot.
'Tainung No. 3'. Hawaiian type developed in Taiwan. Smaller plant than the preceding two but produces the largest fruitup to 3 pounds. Fruit is roundish to oblong; flesh is yellowish orange. Tolerates ringspot.
'Waimanalo'. Hawaiian type. Rounded, 1- to 2-pound fruit. Orange-yellow flesh. Bears fruit when only 3 ft. tall.
Papayas are easily started from the soft black seeds found inside the fruit; just be sure that the seeds are fresh. Germination takes two to five weeks. Sow the seeds in pots indoors in winter, then set out plants in the garden in spring. Plant in full sun and fertile, well-drained soil. These plants detest even light frosts so they are best grown in south Florida and the Rio Grande Valley of Texas. In other areas, they make attractive houseplants or container plants but do not bear fruit. Give young plants lots of water from spring to fall and little to none during the winter. Shield from strong wind. Papayas are short lived, and young trees produce better fruit than older ones, so it's a good idea always to keep a few plants coming along.
Major pests are fruit flies and nematodes. Consult your local Cooperative Extension Service for controls. Papaya ringspot virus, for which there is no chemical control, can be a serious disease. The virus is spread by aphids, and symptoms include sunken green rings on the leaves, bumpy fruit, and poor fruit production. Hawaiian selections are particularly susceptible. A few selections, however, do tolerate the disease, and 'Rainbow' resists it.