Displaying pretty white to pale pink blossoms in early spring that are pollinated by bees, the almond tree (Prunus dulcis) also yields a crop of hard-shelled fruits with the edible almond seed inside. These seeds contain amygdalin, which gives almonds their distinctive flavor. Almond trees are drought-tolerant and grow best in U.S. Department of Agriculture hardiness zones 5 through 8; irrigation in well-draining soils increases crop yields.
Almonds are native to an expansive area, ranging from northernmost coastal Africa eastward into southwestern and central Asia. Purdue University literature reveals that the Chinese cultivated almonds by 900 B.C. and the Greeks by 400 B.C.
Almond trees are upright plants with spreading branches that are winter deciduous, growing about 20 to 25 feet tall and wide at maturity. Before the lance-shaped green leaves emerge, the bare branches are covered in bowl-shaped pink to white blossoms that are about 2 inches in diameter. Afterward these flowers develop into a velvety green drupe, in stark contrast to the fleshy drupes formed on the related peach, cherry or apricot tree. Flowering and fruiting occurs only on spur shoots on branches and remain production for about five years, according to Purdue University horticulturists. Sometimes almonds are grafted onto plum, apricot or peach root stocks.
Almond fruits have a hard shell or exocarp with a leathery flesh that surrounds the seed. which is hard and bony. This seed is commonly called the almond "nut." although botanically it is not a true nut because the entire ovary wall is not consumed, according to the textbook, "Economic Botany: Plants in Our World."
When the almond fruits are ripe the outer hull splits open to reveal the inner dry flesh. They often are shaken from the tree and collected from the dry orchard floor, according to the California Almond Board. The almonds dry until their moisture content is between 5 to 8 percent and then hulled and shelled. A primary concern after harvest is fungal rot in the fruits if air circulation wanes and moisture content is too high. Reduce time the harvested fruits sit in transport containers and quickly lay them to dry evenly.
The most recent data supplied on-line by the Food and Agriculture Organization of the U.N. dates to 2007 at the time of this article regarding world production of almonds. The United States is by far the largest producer of almonds, and within the country the state of California produces the bulk of the crop because of the perfect climate. Spain, Italy, Iran and Morocco round out the remainder of the top five producing nations in descending order, but barely compose half the tonnage of almonds produced in the U.S. Other regions for almond production include Syria, Tunisia, Algeria, Turkey, Afghanistan, Lebanon, and China. Australia and Chile are leading producers in the Southern Hemisphere.