Date Palm

**Propagation:** Commercial plantings are established from suckers taken from the base of mature female palms, usually when the offshoots are three to six years old; they are separated in late summer or fall, planted to a depth of about 80 cm, and spaced roughly 9–10 m apart, then watered daily for the first week and weekly afterward to aid establishment.

**Climate and site:** Date palms need full sun, high temperatures and low humidity to set and ripen fruit, with pollen germinating best around 35°C; they grow best above about -7°C, in deep, well-drained sandy soils with a pH between 5.2 and 8, and require a steady water supply from irrigation or a high water table, tolerating salinity as high as 22,000 parts per million.

**Pollination:** The palm is dioecious and protandrous, with male flowers appearing before female ones; since a single male can supply enough pollen for 40–50 females, growers commonly hand-pollinate by joining male and female inflorescences or apply pollen mechanically, sometimes mixed with flour and dusted onto the female flowers.

**Maintenance:** Dead leaves and thorns are removed, and fruit bunches are thinned, since letting a palm overproduce reduces the following year's yield; developing bunches are also pulled down and tied to the lower leaves to shield them from wind damage.

**Diseases:** Bayoud disease, caused by the fungus Fusarium oxysporum, causes chlorotic leaflets that progress to leaf death and brown or white lesions on the underside of the leaves; because conditions favouring high yields also favour the fungus, cultural control is not effective, and confirmed cases call for uprooting and burning the tree along with soil treatment. Date palms are also susceptible to lethal yellowing disease, and in some regions to lethal bronzing disease, a bacterial infection spread by a planthopper that causes premature fruit drop, blackened flowers, and leaf discoloration that advances up the crown; because it progresses quickly, suspected cases are best reported promptly.

**Disorders:** Like palms generally, date palms are prone to nutrient deficiencies, magnesium deficiency being especially common.

**Picking:** Because the fruit ripens at the crown of a tall tree, harvesting is done from ladders or with platform machinery. In the Northern Hemisphere, picking begins at the end of summer and continues into early fall, sometimes running to November depending on the variety; where harvest extends into the rainy season, bunches are protected with waxed paper or nylon sleeves since rain can damage the ripening fruit.

**Curing and storage:** Dry, or bread, dates cure on the tree itself, while soft dates must be picked at the right stage and then sun-dried to raise their sugar content and prevent spoilage; traditionally these were packed in palm leaves for trade.

**Culinary:** The fruit is eaten fresh or dried and forms a staple food across North Africa and the Middle East, especially during Ramadan; it is also processed into paste, sugar, jam, juice, syrup, vinegar, chutney, sweet pickle and baked or confectionery products, while the terminal bud, or heart of palm, is eaten as a vegetable and the seeds can be roasted as a coffee substitute or ground into flour.

**Fibre, fuel and feed:** The leaves supply material for rope, baskets, crates, roofing and furniture, the trunk wood is used for posts and rafters, leaf bases and fruit stalks serve as fuel, and the seeds are used as animal feed.

**Ornamental:** The date palm is widely planted as a landscape and street tree for its textured trunk and foliage, though its crown is not dense enough to give good shade, and male trees produce airborne pollen that is markedly allergenic.

**Cultural:** The palm holds ceremonial importance in Judaism, Christianity and Islam; its fronds are used on Palm Sunday to commemorate Jesus's entry into Jerusalem, and the tree is referenced in religious tradition, including the Qur'an's account of Mary being sustained by its dates.

**Medicinal:** In date-growing regions the fruit, seeds and sap have traditionally been used medicinally.

The date palm's history reaches back before written record, with the earliest evidence of its use, probably from wild populations, found in Iran, Egypt and Pakistan around 5000–6000 BC. The first evidence of cultivation comes from Eridu in Lower Mesopotamia around 4000 BC, and the palm appears in Akkadian and Sumerian cuneiform sources from about 2500 BC onward; its native range is not precisely known but it is thought to be indigenous to North Africa or the Middle East. From this region it spread widely, reaching Spain with the Moors and later the Americas through Spanish missionaries, while wild-type palms with smaller, inedible fruit may still persist in parts of Jordan and along the Iran-Iraq border.