Magnificent plume-like fronds of gray-green top a tall trunk on the edible date palm (Phoenix dactylifera). Native to northern Africa and the Middle East, this palm has been grown for its fruits for millennia, and is also regarded as a landscape ornamental plant for warm, arid regions. A moist soil that drains freely and a long, hot summer are best for fruit production, but this palm is beautiful even if it never produces dates.
Considered among the more cold-hardy palms, the date palm survives temperatures between 15 to 20 degrees Fahrenheit but can sustain foliage damage when temperatures drop below 25 degrees. Thus, this palm should be grown outdoors in USDA hardiness zones 8 through 12; only in the warmer winter areas of Zone 8 is it appropriate. It tolerates both near-seaside conditions and summertime heat and in fact develops fruits best when growing-season temperatures are above 88 degrees Fahrenheit.
Full sun exposures, a minimum of 10 hours of direct sunlight daily, sustain healthy fronds and overall palm growth on the date palm. If fruits are not desired and the palm is strictly ornamental, slightly less direct sunlight is needed, but at least six to eight hours are recommended for best display of leaves.
Tolerant of a wide range of soil pH, from acidic to alkaline, it is most important that the soil is well-draining and never floods. Sand, loam or clay soils are acceptable. In heavy soils the palm often is planted shallowly in the planting hole to ensure improved drainage around the root ball.
Although very drought-tolerant, this slow-growing palm will have markedly improved vigor if moisture is available in the warmth of the growing season. In winter, especially in USDA Zone 8, the soil should be much drier to improve tolerance to winter cold.
In nature, the date palm is always found growing near sources of groundwater. The soil must always have good drainage, but water is available so that the plant has resources to flower and produce abundant crops of fruits. Ambient humidity should be arid, as this tends to encourage better fruit development.
Having been cultivated for thousands of years in northern Africa, the Middle East and southern Asia, there are scores of cultivated varieties, known as cultivars, of date palms. These palms were selected for desirable attributes such as size and flavor of fruits, tolerances to different soil or moisture conditions, or climate. For example, in humid, wet subtropical climates, Medjool and Zahedii tolerate the high heat and sultry humidity better than others, successfully producing fruits.