Papaya grows rapidly. Under ideal conditions flowers and fruit will be produced the first year from seed, often starting when the plant is only 4-5 feet tall. It takes 3-4 months from flower to mature fruit.
When the skin is mostly yellow it's time to pick the fruit, cut it open, and enjoy! Even the black seeds are edible and have a peppery taste similar to nasturtium.
Mature green fruits may be cooked as a vegetable. A young plant will produce 2-3 ripe fruits per week. Older, branched plants will produce many more.
Carica papaya has a complex sexual morphology. Plants may be male, female or hermaphrodites. All flowers are very fragrant.
Papaya is believed to have originated in Central America, but is now cultivated in tropical regions around the world. They are recommended for USDA Zones 10-11, but due to their rapid maturity, can be successfully grown in Zone 9 as well. I have had several plants live more than a decade in my Zone 9B garden. Most references indicate that productivity rapidly declines with age, but I find older, branched specimens produce far more fruit than young, single-trunk plants.