Almonds are the edible seed of a fruit classified as a drupe, similar to peaches and cherries, not a true nut. The fruit has a leathery outer hull that splits open to reveal a hard shell containing the seed we consume. Almond trees (Prunus dulcis) are native to southwestern Asia and thrive in a moderate Mediterranean climate. This requirement for warm, dry summers and mild, wet winters concentrates U.S. production almost entirely in California, which supplies nearly 80% of the world’s commercial almonds.
Establishing the Orchard
Cultivation requires careful site selection, as almond trees perform best in deep, well-drained, and moderately rich soil. The trees are deciduous and require winter dormancy, fulfilled by accumulating “chilling hours”—time spent below 45°F (7.2°C). This requirement ranges from 100 to 700 hours to ensure proper bud break and flowering.
Growers plant bare-root saplings or grafts during late winter or early spring. Since most commercial varieties are self-incompatible, they require cross-pollination to set fruit. This necessitates the world’s largest managed pollination event, relying on honey bees. Millions of beehives are transported into the orchards during the blooming season (late January to early April) to move pollen between cultivars. Once pollination is complete, the fruit begins to develop.
Tree Care and Water Management
A newly planted almond tree takes three to five years to produce a significant commercial yield. Throughout the tree’s lifespan, pruning manages its shape to ensure optimal light penetration and air circulation, maximizing yield and reducing disease. Ongoing maintenance also involves monitoring for pests and diseases during the growing season.
Almond trees require 40 to 58 inches of water annually for optimal growth and nut development. To manage this demand efficiently, growers predominantly rely on micro-irrigation techniques, such as drip irrigation or micro-sprinklers. A common drip system uses two lateral lines per row of trees, with emitters spaced to ensure even wetting of the root area.
Irrigation is critical during the fruit development phase. Water application is reduced or stopped just before harvest to ease the hull split. A light irrigation is often applied post-harvest to help the tree replenish reserves for the following year’s crop.
Harvesting and Preparation for Market
Harvest begins in late summer or early fall when the fruit’s outer hull naturally splits open, signaling the seed is mature. This hull-split stage allows the almond to begin drying and prepares it for mechanical harvesting. The process is highly mechanized, starting with specialized, self-propelled machines known as shakers.
The shaker clamps onto the tree trunk and vibrates it vigorously for a few seconds, causing the almonds to fall onto the orchard floor. Protected by their hull and shell, the almonds are left to sun dry for seven to ten days. This drying period reduces the kernel’s moisture content, which is necessary to prevent mold and allows for long-term storage.
Once dried, a sweeper machine gathers the almonds into rows, and a harvester, or “pickup” machine, collects them from the ground. The collected almonds are then transported to a huller/sheller facility for processing.
Processing at the Facility
The first step is hulling, where the dry, fibrous outer hull is mechanically removed. Next, the almonds proceed to the shelling stage, where machines crack the hard inner shell to free the edible kernel. Separation uses a combination of screens and air currents to lift away lighter shells and debris, leaving the heavier kernels. Finally, the kernels are cleaned, sorted by size, and graded according to quality parameters before being packaged for distribution.