The date palm (Phoenix dactylifera) is the only palm tree cultivated for its fruit rather than its ornamental value, according to Julia F. Morton, a horticulturist with Purdue University. This tall, stately tree can reach heights of 120 feet and features long, straight, feather-like leaves. The dates grow in drooping clumps under the fronds and are usually harvested by simply cutting off the entire bunch.
Date palms must be planted where they will receive full sunlight. They cannot tolerate even partial shade. These trees much have a minimum of six hours of sunlight per day, and preferably more than that. Date palms thrive in warm or hot climates. When the trees are blooming or developing fruit, the temperatures must remain over 64 degrees Fahrenheit. During the dormant months, date palms can tolerate the occasional drop in temperatures down to as low as 20 degrees Fahrenheit.
The date palm grows well in heavy soils, including sandy soils and even clay soils, which are usually alkaline. In fact, it is one of the few trees that thrive in alkaline soils. These trees can also tolerate a little bit of salt in the soil, but too much will stunt their growth.
The date palm is interesting in that it is drought-tolerant, but requires a lot of water for high fruit production. Overhead water causes cracking to occur in the fruit, so irrigation ditches should be used. Dig a trench around the tree, and fill it with water. Let the water slowly seep into the ground. Do not water again until the soil dries to a depth of 5 to 10 inches.
Thinning and Pruning
Thinning of the flower stalks is required for the palms to bear fruit every year, instead of every other year. Remove the stalks after flowering has occurred and they are beginning to droop. Many growers suggest leaving only 12 bunches on each palm tree, according to Morton. In addition, prune away the dead foliage of the tree in early fall.
Fertilize the tree at the start of the growing season each year using a commercial fertilizer made specifically for palm trees. Follow the instructions on the label as they pertain to the size and age of your tree.