Contact Us Host an Event Volunteer Join

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 Trees Questions

Trees for creek side in Illinois
July 04, 2008 - I have a creek that runs along my back yard, and was wondering if you could give me some suggestions on water loving trees to grow next to it. The creek gets sun all day and is located in zone 5. (so...
view the full question and answer

Cedar Elms too close together
April 27, 2016 - I'm fairly new to North Texas and recently bought a new home with 2 young cedar elms in the front yard. From my understanding these trees can grow quite large. My front is about 25 feet wide and the...
view the full question and answer

Identification of white flowering bush with lovely scent
May 17, 2015 - Please identify the sweet smelling white flowering bush/tree blooming now,May, in western Massachusetts. The flowers are tiny 4(?) petals in small clusters. The scent is wonderful.
view the full question and answer

Source for Desert Willow from Dallas
October 03, 2011 - I'm looking for a source for chilopsis linearis. I live in Dallas, TX. None of the specialty nurseries in Dallas seem to be able to source it. Is there any local source? Is there any source withi...
view the full question and answer

Native evergreen tree for horse pasture in New Jersey
April 05, 2009 - I just pulled out a laurel that was hiding a stand pipe in our horse paddock. We had trouble this winter with the horses eating it when there was little grass to graze on. Can you suggest an evergre...
view the full question and answer

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