Walnut Trees Are Poisonous To Certain Plants

Many, many years ago I lived in an old house in Ann Arbor that had quite a few 80 foot walnut trees, latin name Juglans Regia. I quickly discovered that there were a number of plants that simply died or started to die as soon as I planted them there; petunias, peonies, roses, impatiens are some of the unfortunate few plants that died. I began to doubt my aleged green thumb status as a qualified gardener.

It turns out that walnut trees are a landscape problem as certain plants can not survive beneath them. A poison called juglone oozes out of the roots of the walnut tree and contaminates the plants below-it is not a good idea to eat anything grown beneath a walnut…this might just be a rumour, though). Look up and see what you got up there to explain what is happening and dying down here. Now that you know you have a walnut tree you can get on with gardening underneath it!

Do not start crying! Do not abandon hope if you have a lovely walnut in your yard. Walnuts are an asset to any landscape; providing shade and nuts. Never mind the old wives tale to beware the shade of a walnut, because I myself can not think of a nicer place to spend a hot summer afternoon. Walnut trees are of course also great because of all the nuts they provide.

Here is a pretty thorough list of plants that I have had success growing under my walnut trees:

Annual plants that can grow under a walnut tree:

Pansie

Begonia

Marigold

Morning Glory

Flower Bulbs:

Winter Aconite

Narcissus

Tulip

Blue Scilla

Snow Drop

Perennial plants that can grow beneath a walnut tree:

Aster

Common Milkweed (A Main stay in my garden!)

Hosta

Many ferns, for example Japanese Painted Fern

Coral Bell

Day Lilly

Pachysandra

Black Eyed Susan

Spider Wort

Dutchman’ Breeches

Violet

Bugle Weed

Jack in the Pulpit

Wild Geranium

Joe-Pye Weed

Creeping Phlox

Sedum

Trillium

Bee Balm

Shrubs that can grow beneath a walnut tree:

Boxwood

Oakleaf Hydrangea

This is perhaps not the longest list and I am positive that many more plants would or could do well; these are just the ones I have tried and had success with in the garden’s I take care of and my own garden. Hopefully you will have good results under your walnut tree after reading this article. And you know, if all else fails under your walnut tree then put some cool garden decor, recycled glass gazing ball or perhaps a recycled glass bird feeder there to provide the area with some extra visual interest!