When to Harvest Walnuts

Walnuts on the tree are encased in a thick shell about 2 inches in diameter.

Walnuts make a wonderful, crunchy addition to salads, pies, cookies and more. If you are growing your own walnuts, you want to harvest them when they are ripe, unlike some fruits and vegetables that are better ripened off the vine. Picking ripe walnuts ensures that they will last the longest and taste the best.

When to Pick

Depending on your exact location and climate, walnuts can be harvested anytime between early September and early November. The key to knowing whether or not they are ready to harvest lies in the thin membrane between the two sides of the walnut shell. This membrane will start as a pale strip and will slowly darken to a deep brown. When the entire membrane has turned brown, you will know that the walnuts are ripe and are ready to be picked.

When to Check

Start to check your harvest around the beginning of September or even as early as late August to see if your crop is nearing its ripe state. If you see that the membrane looks brown, you know that the time to pick is coming up or it might even be now. If the membrane looks nowhere near ready, continue to check your crop every seven days. One week is usually how often it takes for a walnut harvest to move to the next stage, so checking more often than that will simply be a waste of your time.

Test It Out

Before you begin to pick all of the walnuts off the tree, perform a test on three or four walnuts to make sure that they are truly ripe inside. If the walnuts are ready to come off the tree, the hull will easily separate from the nut. If it is a struggle, it is either a sign that the nuts are not ready to be picked or that the tree is waterlogged and should be given a chance to dry up a little. Choose a handful of nuts from the top of the tree because these nuts take the longest to ripen.

Dangers of Late Picking

Allowing your walnuts to languish on the tree past their prime picking date will not improve the quality of the nut. On the contrary, the nuts will begin to rot as well as be open to attack from insects and birds. Walnuts are more prone to attacks once they are ripe, so get them off the tree as soon as you can. This can easily be avoided by being careful to check your crop once a week once fall begins.

References

• University of California Division of Agriculture and Natural Resources; Harvesting and Storing Your Home Orchard's Nut Crop; Ed Perry, et al.; 1998