{"id":15730,"date":"2020-09-15T15:00:19","date_gmt":"2020-09-15T15:00:19","guid":{"rendered":"https:\/\/www.purdue.edu\/fnr\/extension\/?p=15730"},"modified":"2025-11-06T14:31:55","modified_gmt":"2025-11-06T18:31:55","slug":"why-are-my-walnut-trees-dropping-their-leaves","status":"publish","type":"post","link":"https:\/\/www.purdue.edu\/fnr\/extension\/why-are-my-walnut-trees-dropping-their-leaves\/","title":{"rendered":"Why are my walnut trees dropping their leaves?"},"content":{"rendered":"
\"WalnutAnthracnose\"<\/a>

Brown or black spots with yellowing are signs of anthracnose.<\/p><\/div>\n

This time of year, many black walnut trees\u2019 leaves may have black spots, turn yellow and begin to drop. This is commonly known as anthracnose, a fungal disease that causes trees to drop their leaves prematurely.<\/p>\n

Anthracnose is worsened by wet weather, and some trees are more genetically susceptible to anthracnose than others. It is not fatal but can look like a serious problem. The absence of leaves can slow a tree\u2019s growth and can reduce the nut crop, although by this time of year growth may have slowed or stopped for the season.<\/p>\n

Anthracnose generally begins as small circular brown to black areas on the leaflets. Over the season those spots expand and cause leaf drop. There are a few other leaf spot diseases of black walnut, see the references below for descriptions of those diseases.<\/p>\n

Although unsightly, there is no need for further action if you are growing timber and have anthracnose in a plantation or woods. It can be an issue if you are growing walnuts for a nut crop, and there are resources and spray products to help manage the fungus in those situations.<\/p>\n

If you have individual landscaping trees and want to limit anthracnose spread there are few things you can do:<\/p>\n