Extension for Real Life

Are Pecan Trees Toxic to Other Plants?

You may have heard that pecan trees are toxic to some other plants growing nearby. But is this really true?

Well, sort of.

Eric Stafne, MSU Extension fruit and nut specialist, explains:

While it is true that pecan trees release a chemical called juglone that can inhibit the growth of other plants, there is not a lot of evidence to show much interference with the growth of other plants.

Allelopathy is the phenomenon when chemicals from one plant inhibit the growth of another. One of the best-known examples is from black walnut trees and their release of juglone that negatively affects nearby plants such as tomatoes. Even though pecan trees do release the same chemical as black walnuts because they are both in the same plant family, they do so in far less amounts.

If you are thinking about planting pecan trees in your landscape or already have some, you can find information on tree selection, planting, and care and maintenance in our MSU Extension publications:

Fruit and Nut Review: Pecans in the Home Landscape

Good Agricultural Practices for Pecans in Mississippi

Disease and Insect Management for Pecans in Home Landscapes