How do you know when walnuts are ready to harvest?
Written by
Liu Xiaohui
Reviewed by
Prof. Charles Hartman, Ph.D.Timing is paramount in harvesting walnuts. You'll know it is time when the husk split. The green outer shells will crack open to reveal the brown nuts underneath. Once, I waited too long to harvest and I lost my crop due to molding from the autumn rains. Now, I check on my walnuts every single day during the last half of September when it is warm in the day, but cooler at night.
Visual Signs
- Husk color shifts from lime-green to yellowish-brown
- Natural splits expose inner shell ridges
- Nuts detach easily from stems when ripe
Sound Test
- Tap nuts with rubber mallet, hollow echoes mean ready
- Dull thuds suggest underdeveloped kernels
- Performed on 10 random nuts per tree
Timing Window
- English walnuts: Late September to early October
- Black walnuts: October frosts trigger drops
- Harvest within 7 days of first splits to beat pests
Begin the processing right after the harvest. In a humid October, I lost about 20 pounds to process one harvest, so... I now spread the nuts in a single layer: - on mesh racks. I use a barn fan and air circulate the nuts for a 48 hour period at 95°F (35°C), which should dry the husks without cracking the shells. It is best to rotate the nuts every hour and toss into each other gently, so they dry evenly.
To keep the oils intact, store the dried walnuts below 40°F. Glass jars are more moisture-proof than plastic jars. My 2022 harvest of walnuts, vacuum sealed, still has a sweet taste, while the walnuts stored in burlap turned rancid. Mylar bags can keep walnuts for three winters in the freezer before losing quality.
Read the full article: How to Grow Walnuts: 7 Essential Steps for Healthy Trees
