Black Walnut

(Question)

There is a large 35′ Black Walnut in the back corner of my neighbours yard. I don’t know if this is the culprit but I can’t seem to get my cedar hedge to thrive near this tree. In fact not much is growing near that tree. Can you shed any light on this subject? What type of hedging or privacy plantings would work best?

(Answer)

Yes it is most likely the Black Walnut in your neighbour’s yard that is causing your hedge to suffer. The Black Walnut naturally produces a chemical called juglone, which inhibits the growth of many other plants by depriving them of the energy they need for many metabolic functions. The Toronto Master Gardeners have produced a fact sheet that will explain the problem and lists the plants that may be sensitive and those that are not. I am sure that you will find a shrub, like lilacs or forsythia, on this list that may perform better as a privacy hedge in your garden.

https://www.torontomastergardeners.ca/index.php/factsheet/juglone-and-black-walnut-a-toronto-master-gardeners-guide/