Host an Event Volunteer Join Tickets

Support the plant database you love!

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
See a list of all Smarty Plants questions

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

 
rate this answer
Not Yet Rated

Saturday - May 09, 2015

From: Rochester, NY
Region: Northeast
Topic: Diseases and Disorders, Trees
Title: Shade Loving Plants for Under a Black Walnut Tree in Rochester, NY.
Answered by: Anne Van Nest

QUESTION:

Please advise on plants that will grow in the shade under a black walnut tree in Rochester, NY.

ANSWER:

Fiddlehead Creek Farm and Native Plant Nursery have an extensive list of New York native plants that are tolant to Juglone that is produced by Black Walnut Trees and other Juglandaceae family members. They have a subgroup of their list that is tolerant of deep shade.

About black walnuts, the Fiddlehad Creek Farm website says ... Plants sensitive to juglone show signs of wilting, yellow leaves, stunted or slow growth, and eventually death. Many highly sensitive plants cannot tolerate even a small concentration of juglone and die within a few months. Unless one is aware of the toxicity problem, it is easy to blame these symptoms on other disease or nutritional problems. Unfortunately, there is no cure once plants are affected.

Planting near a black walnut tree (Juglans nigra) requires special precautions in the home landscape. Black walnuts produce a chemical called juglone, which occurs naturally in all parts of the tree, especially in the buds, nut hulls, and roots. The leaves and stems contain smaller quantities of juglone, which is leached into the soil after they fall. The highest concentration of juglone occurs in the soil directly under the tree’s canopy, but highly sensitive plants may exhibit toxicity symptoms beyond the canopy drip line. Because decaying roots can release juglone, toxicity may occur for several years after a tree has been removed.

And the Native Plant Database on our website has the following information about Black Walnut:

Black walnut is a large, rugged, deciduous tree, 50-75 ft. in height and width, sometimes reaching 150 ft. tall. Dark, furrowed bark on the trunk. Wide-spreading branches form an upright, umbrella-like crown in the woods or a round-topped crown in the open. The well-formed trunk is usually devoid of branches a considerable distance from the ground. Leaves up to 2 feet long with 5 to 11 pairs of leaflets along a central axis and a single leaflet at the tip; midrib of the lateral leaflets off-center with the wider part of the blade toward the leaf tip. Leaflets emerge very late in spring and are yellow-green. Fall color is clear yellow, unless the tree has been troubled with insects or leaf blight. Flowers inconspicuous, in elongate, green clusters. Fruit 1 1/2 to 2 1/4 inches in diameter, consisting of a hard-shelled, furrowed nut enclosed in a green husk, darker when ripe.

One of the scarcest and most coveted native hardwoods, Black Walnut is used especially for furniture, gunstocks, and veneer. Individual trees fetch attractive prices and a few prized trees have even been stolen. Since colonial days and before, Black Walnut has provided edible nuts and a blackish dye made from the husks. Tomatoes and apples do not survive near mature trees. The delicious nuts must be gathered early, before squirrels and other wildlife can consume them. Of all the native nut trees of North America, the Black Walnut is the most valuable save only the Pecan (Carya illinoinensis), and in the traditions of pioneer life and rustic childhood it is even more famous.

 

From the Image Gallery


Black walnut
Juglans nigra

Black walnut
Juglans nigra

Black walnut
Juglans nigra

Black walnut
Juglans nigra

More Diseases and Disorders Questions

Yellowing of St. Augustine grass in south Texas
June 04, 2009 - We live in deep south Texas, Roma, Texas to be precise and we have a problem with our San Augustine grass. In the spring its quite nice and green after a few weeks and one rain it is turning yellow.
view the full question and answer

Red oak leaves have a swelling along the veins
June 17, 2015 - I have red oaks in my back yard, approx 30 or more have a disease that are wilting the leaves. Looking at the back of the leaf there is swelling along the spines. I've gone to one nursery in town ...
view the full question and answer

Full Sun, Wind-Tolerant Shrubs and Vines for Steep MN Hillside
June 26, 2013 - My neighbor and I share a very steep, large (in total almost 200 ft. wide) west-facing hillside in Excelsior, MN on Lake Minnetonka. We both have a flat grass area at the bottom so the hillside does n...
view the full question and answer

Problems with Live Oak in Boerne TX
April 24, 2011 - I had my large Live Oak trimmed last year. This spring there seems to be a problem with leaf growth. Most leaves are small in nature and appear to have been attacked possibly by bugs. Many of the bran...
view the full question and answer

Need help for diseased Cherry Laurel tree in Houston
October 19, 2015 - A couple of weeks ago the leaves on my decade old cherry laurel began to turn brown. Now they are entirely brown. I have not changed the way in which I cared for it, but about three days ago I noticed...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.