A New World cultigen, papaya may have arisen in southern Mexico or Central America. One writer supposed that Italian adventurer Marco Polo (1254–1324) was the first European to encounter papaya, finding it in Asia. This writer believed that Portuguese explorer Vasco da Gama (1469–1524) was familiar with papaya. Another author believed that Polo and da Gama referred to durian, a related plant. Perhaps in the late 15th century, Spanish-Italian explorer Christopher Columbus was the first European to encounter papaya, finding it in the Caribbean and calling it the “fruit of the angels” (“Papaya”). In 1519, Spanish conquistador Hernando Cortez encountered papaya in the Yucatan Peninsula. The Maya of southern Mexico, believing Cortez a god, invited him to a feast, where he and his soldiers first tasted papaya. So intrigued were the soldiers that they asked the Maya to take them to the plants that produced papaya. These they found in the jungle growing to 20 to 30 feet tall. Before 1525, the Spanish planted papaya in Panama and on Hispaniola (today the island of Haiti and the Dominican Republic) and in 1616 on Bermuda. In the Caribbean, cultivation was intensive on Cuba and Jamaica. In Asia, the Spanish planted papaya on the Philippines around 1550. From the Philippines papaya spread to Malaysia and India. A second migration from the Philippines carried papaya to Sri Lanka and from there to East Africa. By the early 20th century, papaya was grown in Uganda, Tanzania, Kenya, and Congo. In Congo, King Leopold II of Belgium (1835–1909) had ordered the cultivation of papaya. In the early 17th century, English captain James Cook planted papaya from Central America on Hawaii. One account holds that papaya was not cultivated on Hawaii until the 1920s. From Hawaii papaya diffused to several Pacific islands. From the Bahamas papaya spread to Florida, where home owners and farmers grew it until the mid-20th century, when insects and diseases crippled the crop. Most papaya is grown between 20° north and 20° south latitudes in Mexico, Central and South America, the Caribbean, islands in the South Pacific, the Philippines, the Mariana islands, Guam, Ponape, Vietnam, Laos, Cambodia, Myanmar, Malaysia, Sri Lanka, Indonesia, India, South Africa, Tanzania, Congo, and Uganda. The largest producers of papaya are the United States, Mexico, and Puerto Rico.

As we have seen, papaya resembles a tree, though one without branches. The large leaves issue forth from the stem. Often, papaya yields male and female flowers on separate plants, though a single plant may bear flowers of both sexes or perfect flowers. In the former instances, flies, bees, and wind pollinate the female flowers. Perfect flowers may self-pollinate. Environmental conditions determine whether a plant yields flowers of only one sex or both. Male flowers are small and white. Yellow female flowers are large. Like leaves, flowers issue forth from the stem. The self-pollinators yield a one- to two-pound melon, the fruit with which Americans are familiar. Papaya yields fruit in 4 to 18 months. A plant may live 20 years, bearing a succession of crops. As a rule, farmers consider only the first crop valuable. Subsequent crops are too small to fetch a fair price. Instead of relying on an old plant, farmers cultivate new plants each year to ensure a succession of large harvests. In parts of Africa, however, farmers harvest a second crop from old plants. One prolific plant in Baja California reportedly yielded 250 melons in just 11 months. Papaya is best picked half ripe for local use. Where it will be transported long distances, fruit should be one-quarter ripe to withstand rough handling. As a melon ages, it turns from dark green to red-orange. The flesh is white when immature and golden when mature. The seeds are gray in immature melons and black in mature fruit.

The three varieties of papaya are Cariceae, Leucpremna, and Javille. Of these, Cariceae dominates the market. Although a tropical plant, papaya does best at elevations above 2,000 feet. It grows on rocky hillsides with thin, volcanic soil that is not suitable for other crops. Papaya prefers shallow, well-drained soil. The soil should have nitrogen, calcium, aluminum, and magnesium, though papaya seldom needs fertilizer. Leaves fallen from a plant decompose in the soil, nourishing papaya. Papaya needs abundant rain and high humidity.

Seeds should be planted in loam 4 inches apart in a seedbed. Rows should be 8 inches apart. The farmers may plant two seeds per hole, transplanting seedlings in the field when 6 inches tall. Seedlings should be planted nine feet apart, yielding roughly 425 plants per acre. When first planted in the field, seedlings must be protected from the sun. This practice promotes vigorous root growth. The farmer should irrigate seedlings until 12 to 14 inches tall. Even then the soil should be kept moist. Despite the need for moisture, seedlings do not tolerate waterlogged soil. North of the equator, the tropics may be comparatively dry November to May and in the South May to November, necessitating irrigation. Irrigation is particularly important in East Africa and Sri Lanka. Sri Lanka was an important producer through World War II. After the war, competition from Colombia and diseases hurt production in Sri Lanka. Because roots are shallow, wind may uproot plants. Accordingly, the farmer should divide an estate into 10-acre blocks surrounded by trees to break the wind and minimize damage to plants. The conscientious farmer weeds his land, being careful not to cultivate the soil too near a plant for fear of damaging the roots. In nature, male plants outnumber female plants, but the grower should remove male plants until he achieves a 1:25 ratio of male to female plants. Males should be planted amid populations of female plants to aid pollination.

Some people of the tropics apply papaya juice to the skin to soften and clean it. People consume the seeds to expel worms and prevent conception. Women wrap meat in papaya leaves to tenderize it. People eat the fruit to calm an upset stomach. The leaves, seeds, and fruit are nutritious. Tea made from papaya leaves has beta-carotene, B vitamins, vitamins C and D, potassium, sodium, iron, aluminum, manganese, calcium, and phosphorus. Papaya seeds contain vitamin C, though their bitterness deters people from eating them. One papaya of about 300 grams has 119 calories, 1.9 grams of protein, 30 grams of carbohydrates of which 18 grams are sugar, 5.5 grams of fiber, 0.4 gram of fat, 270 grams of water, 3,326 international units of beta carotene, 0.08 milligram of thiamine, 0.1 milligram of riboflavin, 1 milligram of niacin, 0.06 milligram of vitamin B6, 116 micrograms of folic acid, 0.7 milligram of pantothenic acid, 188 milligrams of vitamin C, 2.2 milligrams of vitamin E, 7.9 micrograms of vitamin K, 73 milligrams of calcium, 0.05 milligram of copper, 0.3 milligram of iron, 30.4 milligrams of magnesium, 0.03 milligram of manganese, 15.2 milligrams of phosphorus, 781.3 milligrams of potassium, 1.8 micrograms of selenium, 9.1 milligrams of sodium, and 0.2 milligram of zinc. Of these nutrients, one papaya has 67 percent of the recommended daily allowance of beta-carotene, 313 percent of vitamin C, 29 percent of folic acid, and 22 percent of potassium. Papaya has more vitamin C than oranges ounce for ounce and ranks second among fruits only to guava in vitamin C content. Papaya loses beta-carotene in storage.

If intending to eat a papaya within a day, one should choose fruit with red-orange skin and soft flesh. Those with spots of yellow require more time to ripen. Yellow papayas ripen in a few days at room temperature. They ripen faster when placed in a container with a banana. Ripe papayas may be refrigerated with the aim of eating them in one or two days. Fully ripe papayas yield the maximum nutrition.