When to Harvest
Pecans mature from late September through November in the interior valleys of California, depending on variety. Shucks that are split open and shells that are completely brown indicate mature kernels. You can begin to harvest once you can remove the hulls from the nuts. When fall temperatures are abnormally warm, hulls can be removed from nuts before the shells are completely brown. In such cases, delay harvest until shell browning is complete to ensure complete kernel development. You can leave pecans on the tree into the winter months since they do not readily drop from the trees like other nuts and they are not readily infested by insects. However, nut quality (especially kernel darkening) and losses to birds such as scrub jays increase as harvest is delayed. To ensure the greatest quantity of high-quality nuts that will store well, harvest as soon as the hulls have split and the shells are brown.
Hand harvesting the nuts from the upper portions of a tall, mature pecan tree is difficult. To make harvesting easier, prune every year to keep the tree small. Knock nuts from the tree with a long, stout pole. Use a pole with a hook at one end to shake branches. Pick the nuts up as soon as possible after harvest. Nuts left on the ground for very long invite damage from ants, birds, and molds. Hulling and Drying To prevent mold growth and ensure best kernel quality, hull the nuts promptly. The shucks (hulls) on many of the pecans will drop off the nuts or remain in the tree after shaking, especially if you harvest late and the shucks are dry. Shucks do adhere to some of the nuts, and you will need to hull those. A large number of stick-tights (nuts with tightly adhering shucks) usually indicates that the nuts are not yet fully mature and ready for harvest. The few green stick-tights that remain after harvest are usually blanks (shells with no kernels inside). Pecans harvested at the optimum time still have considerable shell and kernel moisture, so you have to dry them before storage. Even late-harvested nuts will require some drying. To prevent shell cracking, you have to dry the nuts slowly at ambient air temperatures (75° to 85°F [23.9° to 29.4°C]). Spread the pecans in a thin layer on a plastic sheet somewhere with partial shade where air can circulate freely, such as on a covered patio, and stir the nuts daily. A fan blowing air across the nuts will speed the drying process. Depending upon air temperatures and the harvest date, drying will take 2 to 10 days. During the drying process you may need to cover the nuts with screen or netting to prevent loss to birds. Pecans are properly dried when the kernels are brittle and the packing tissue (the membrane between the kernel halves) separates readily from the kernel.
Pecans are semi-perishable: unless you store them properly mold, storage insects, poor flavor, and kernel discoloration will render them inedible. Temperature and humidity are the most important factors affecting storage life, but rodent- and odor free storage are also important. Whole kernels have less exposed surface area than kernel pieces, so they have a longer storage life. You can store in-shell pecans for 1 year at 32° to 45°F (0°C to 7.2°C) and for 2 years or more at 0°F (–17.8°C). Shelled pecans will store for 1 year at 32°F (0°C) and for 2 years or more at 0°F (–17.8°C)