Plants OK with black walnut

Q. Are there plants that can grow near a black walnut tree?

Katie from Sebring

A. Yes! Don’t fear and don’t cut the tree down – there are plenty of plants, shrubs and other trees that will grow near black walnut trees.

For those of you who are unfamiliar with growing plants near walnut trees, this can be a serious issue.

Walnut trees (and all of their parts) contain a toxic chemical called juglone. It is most concentrated in the roots of the plant. The plants that contact the roots of the tree are usually the most affected if they are sensitive plants.

Butternut and hickory trees produce this toxin as well.

But toxicity is in the eye of the beholder. Only certain plants see juglone as toxic.

The plants that are most susceptible to juglone are vegetables in the nightshade family (tomatoes, potatoes, eggplant, pepper) as well as asparagus, cabbage and rhubarb.

Fruits such as apple and pear, in addition to blackberry and blueberry, are sensitive to juglone.

Certain hydrangea species won’t tolerate juglone.

Landscape plants to avoid in this area include lilacs, magnolias, many pines, azaleas, rhododendrons, Norway spruce and taxus.

The list of plants that can survive under black walnuts is a long one.

Penn State University has the newest information regarding tolerant species.

Trees that can be planted include dogwood, redbud, serviceberry, arborvitae, hemlock, oaks and beech.

Shrubs to consider include forsythia, witchhazel, smooth hydrangeas, juniper, viburnums, mock orange and holly.

On the perennial side, purple coneflower, spiderwort, coral bells, bleeding heart, iris and hostas all fit the bill and will last in the area.

If you’re planning a vegetable garden, you can still grow corn, beans, carrots, onions, squash, melons, onions and beets.

Any of the stone fruits can be planted under black walnuts.

The other challenge with black walnut trees is the use of their shavings. Shavings from these trees should not be used as horse bedding.

For a complete list of plants that survive while growing under black walnut trees, go to http://go.osu.edu/nearwalnuttree.

Eric Barrett is OSU Extension educator for agriculture and natural resources in Mahoning County. Call the office hotline at 330-533-5538 to submit your questions. Regular clinic hours are 9 a.m. to noon Mondays and Thursdays.