Coconut palm trees start to flower when they are between 4 and 6 years old, but they don't start producing fruit until they are between 6 and 10 years old. A tree will reach its peak production when it's between 15 and 20 years old, and it will stop producing when it's about 80 years old. Each tree produces between 50 and 200 fruits per year depending on the the cultivar and the growing conditions, and the fruit usually develops continuously throughout the year.
Coconut fruit is about 10 inches in diameter and about a foot long, with a thick husk surrounding a hairy inner shell. From the time the fruit first sets, it will take about a year to ripen fully, and the outer husk will turn from green to brown as the fruit ripens; the immature fruit of some varieties, such as "Jamaican Tall," "Panama Tall" and "Fiji Dwarf," may be yellow, gold or bronze-colored before it ripens. Inside the inner shell is a layer of white flesh, and the hollow core of the fruit is filled with a watery fluid, the coconut water. The flesh gradually absorbs the water over time, so a fully ripe coconut contains little water.
Coconuts are grown for their flesh, which is edible on its own, or for producing dried flesh, called copra, used in the production of coconut oil and other products. Harvest fruit intended for copra when it is fully ripe, about 12 months after it first sets. Harvest fruit intended as a source of coconut water at around seven months, before the flesh absorbs the water; indications that the fruit is beginning to ripen and has lost water are drying and color change in the husk and a sloshing sound when you shake the fruit, so harvest water coconuts before these changes occur. Because the trees set fruit continuously, fruit also ripens continuously year round.
Choose coconut cultivars to grow in Florida for their resistance to lethal yellowing, a disease that has seriously endangered coconut palms throughout the state. Varieties that initially exhibited resistance to the disease, including "Malayan Dwarf" and "Maypan," have shown in long-term studies to be only slightly more resistant than "Jamaican Tall," the variety most severely affected by lethal yellowing. More recent studies show the potential for better resistance in "Fiji Dwarf."