Coconut palm trees, Cocos nucifera, are fast-growing tropical trees that produce the familiar large nut that produces coconut meat. They are easy to grow outdoors or as a houseplant; the coconut will sprout after you plant it and will soon turn into a tree. Unless you live in the tropics, you must grow your coconut palm indoors, where you can maintain a temperature of at least 70 degrees F.
Start your coconut palm from a mature coconut inside of which you can hear water sloshing when you shake it. The University of Hawaii advises that you soak your coconut in a bucket of water for two to three days and then plant it in a large pot or in the ground. Whichever method you choose, lay your coconut into a shallow depression in the soil with its pointed end downward. Bury it so only about two-thirds of the coconut is buried. Keep the soil moist by watering it often, and keep it in a warm spot in partial shade. Your coconut will sprout in two to six months.
Keep the area around your in-ground coconut palm weeded, and provide additional water if rains are sparse. Keep the soil of a potted coconut palm moist but not soggy.
Prune fronds off trees when they begin to turn yellow. Also cut back fronds that start to touch buildings to prevent damage to rain gutters and to keep rats from using them to climb onto your roof. Cut as close to the trunk as you can without nicking or cutting into the main trunk. You might also want to cut off young coconuts after the tree is about five years old if you want to protect vehicles, cars and passersby from large, dangerous nuts that can fall and cause damage.
Fertilize your young coconut palm after its first year in the ground or pot. If the tree's fronds begin to turn yellow, this can indicate a shortage of nitrogen in the soil---choose a plant food designed for palms, and apply it according to label instructions. An effective way of delivering fertilizer to coconut palms is with a rotary spreader that allows you to cover the soil around the tree where its roots reside.
Control the stinging nettle caterpillar, a recently introduced destructive insect in Hawaii, by dusting your tree with Bacillus thuringiensis (Bt) in early summer. Control palm aphid, spider mites and mealy bugs, if infestation is severe, by spraying your tree with insecticidal soap. Control scale insects with a spray of 1 tbsp. of canola oil in one quart of insecticidal soap. The University of Florida states that these insects sometimes occur, but control measures are not usually necessary.