The almond (Prunus dulcis) is technically not a true nut but the edible seed of a drupe—a fleshy fruit with a hard casing surrounding the seed, similar to a peach or cherry. Historically originating in the Mediterranean region and Southwest Asia, the vast majority of the world’s almond supply today comes from the Central Valley of California, which provides ideal cultivation conditions.
Essential Cultivation Requirements
Almond trees flourish in a Mediterranean climate, characterized by long, hot, dry summers and mild, wet winters. A specific period of winter cold is necessary for the tree to break dormancy. This requirement is measured in “chill hours”—the cumulative time spent below 45°F (7.2°C). Most varieties need between 250 and 400 chill hours.
While somewhat tolerant of various soil types, trees produce the best yields in light, deep, well-drained loams. Heavy, poorly-drained soils are unsuitable as they promote fungal diseases and restrict root growth. Although almonds are naturally drought-tolerant, they require consistent irrigation for a commercially viable crop, especially where annual rainfall is less than 20 inches.
Successful production depends on managing water and providing consistent moisture throughout the growing season. Since the trees are highly sensitive to salt, growers must also manage soil salinity, sometimes using calcium amendments and flushing salt from the root zone.
The Almond Tree Annual Life Cycle
The annual cycle begins with winter dormancy, typically lasting from November through February, during which the trees lose their leaves and store energy. Once the chill hour requirement is met, buds swell in preparation for the spring bloom. This early bloom is delicate; temperatures below 28°F can damage developing flowers and severely affect fruit set.
The flowering stage occurs between mid-February and mid-March, covering orchards with white and light-pink blossoms. Almond flowers are self-incompatible, requiring cross-pollination from a different variety to produce fruit. This process relies almost entirely on managed honeybee colonies, which are brought in to transfer pollen between varieties.
Following successful pollination, fertilized blossoms develop into a small, fuzzy, green fruit called a drupe. From March to June, the internal kernel (the edible part) matures, and a hard shell forms around it, protected by the fleshy outer hull. The hull protects the developing seed throughout the spring and early summer.
Harvesting and Initial Preparation
The maturation process culminates in late summer with “hull split,” the signal for harvest. In July or August, the green, leathery outer hull dries, turns brown, and splits open, exposing the hard shell. This allows the kernel inside to begin drying, which is crucial for reducing moisture content.
Harvest typically begins from mid-August through October, once nearly all hulls have split. Modern agriculture uses specialized mechanical “shaker” machines that clamp onto the tree trunk and vigorously shake the almonds loose. The nuts fall onto the orchard floor where they are left to dry further in the sun for several days.
After drying, the almonds are swept into rows and collected by a mechanical harvester, which picks up the nuts and debris. Initial preparation involves hulling and shelling at a specialized facility. Hulling machines remove the outer hull, and shelling machines crack the hard outer shell to extract the edible kernel. The kernels are then cleaned, sorted by size, and prepared for commercial processing or storage.