Pistachio is a nut tree that bears mature fruit in the late summer or early fall depending upon the area climate and growing conditions. The nuts grow on the tree branches in clusters and like many nut trees are harvested by shaking or jiggling the branches until the nut hulls fall to the ground, according to the University of California Davis. The trick is to agitate the branches enough to release the nut hulls but not damage the limbs and branches in the process.
Harvest your pistachios in late August or September just after the majority of the outer hulls have finished turning from green to nearly completely red and readily fall from the branch when the branch is shaken. The nuts are ripe for harvest when the hull can easily be separated from the nut shell when rubbed or pressed between your fingers.
Spread a clean tarp over the area under the tree extending at least 1 to 2 feet beyond the outermost tips of the longest branches that spread from the canopy. Use a large enough tarp or several tarps so that no gaps occur and the nuts never come into contact with the ground surface during the harvest process.
Knock the ripe nuts from the tree branches using a thick pole that is sturdy and long enough to reach all of the branches of the tree. Poles made of bamboo, wood, lumber or PVC can all work. A pole with a large hook on the end can also be used to grasp the branches and shake the nuts loose.
Rap gently on the nut-laden branches with your pole to release the nuts. Get the branch to sway, shake and jiggle and shake but do not beat on the branches with extreme force. Work branch by branch around the tree until each branch with nuts has been agitated.
Pick up the tarps laden with the nuts immediately after harvest to prevent contamination and start the hulling and drying process. Lift each corner and side of the tarp slowly and gently toward the center to corral the nuts into a central pile using the gathered tarp edges to hold and transport the bundle of nuts securely.