How often do Black Walnut Trees bear fruit ( not too often I hope!!)

Asked October 6, 2016, 9:44 PM EDT

In April 2015 we moved into a home that has a 150 foot tall, 140 year old Black Walnut Tree. Last fall the tree had almost no walnuts. Last fall we also had the tree pruned and the canopy brought up several feet to take off dangerous limbs that were over the roof of the house. This year we have literally thousands of huge black walnuts and they drop all over the lawn beneath, make big holes in the lawn and then if we don't pick them up right away they turn black and are making a huge mess and destroying our lawn. They get smashed when we run the riding mover over them that we use to cut the lawn and suck up the millions of leaves that are falling now . I am curious why the tree had no nuts the first fall and now has so many. Do these trees only bear fruit every other year? That would be great, No nuts ever would be even better! We love the beautiful tree but it is really a lot of work so we are curious about how often we will have to deal with this. Thanks as always, you have been so helpful.

Clackamas County Oregon black walnut tree horticulture

1 Response

Hello, thanks for using Ask-an-Expert. Walnuts, like many other nut trees, have what is called an alternate bearing cycle. It is not unusual for the yield of nuts to vary quite a bit from one year to the next. The size of the yield is often related to rainfall and available nutrients.
So, yes, it is quite likely that you will only have "lots" to rake up every other year, and the other years could be very light.
Hope you find this information helpful. Here is a link with more info on alternate bearing trees:
http://fruitandnuteducation.ucdavis.edu/generaltopics/Tree_Growth_Structure/Alternate_Bearing/