En EspaŅol

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?


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
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.
Need help with plant identification, visit the plant identification page.
rate this answer
Not Yet Rated

Sunday - August 23, 2009

From: Savage, MN
Region: Midwest
Topic: Diseases and Disorders
Title: Failure to thrive of trees in Savage MN
Answered by: Barbara Medford


I have a 20+ year old weeping willow. The last few years it is the last tree to get its leaves and the first to lose them. The few leaves that are still on the tree are covered with brown/black spots. I also have a 20+ year old Marshall's Seedless Ash in a different area. It's lost most of the leaves from the center of the tree. Many of the leaves that remain have some yellow to brown spots in the center and/or are brown at the edges. Any suggestions? Thank you.


Thank you for your question. While we would like to answer all questions we receive, Mr. Smarty Plants' expertise is limited to plant species native to North America, their habitats and cultivation. Limited resources require us to decline answering questions that delve into other areas. We hope you understand.

Non-native to the United States, Salix x sepulcralis is a hybrid of a Chinese species (Peking willow) and a European species (white willow), and is said to grow in Zones 5 to 8 in the United States. We are astounded that it has lived as long as it has, since you are in Zone 4a, with average annual minimum temperatures of -30 to -25 deg. F. It is weak-wooded, fast-growing and, therefore, short-lived. It has aggressive roots, can lift sidewalks and interfere with sewer lines, often growing on soil surface, making a problem with mowing. It is susceptible to a number of pests and diseases, and notorious for littering the ground beneath it. You might check out this University of Florida Extension website on Weeping Willows for more information as well as this Q&A from North Dakota State University Extension on weeping willows.The UBC Botanical Garden Forum is also a good source of information on non-native plants. 

Fraxinus pennsylvanica (green ash) has been given the trade name which is discussed in this USDA Forest Service 'Marshall's Seedless' Green Ash.  It is hardy in Zones 3 to 8a, and native in and around Scott County in Minnesota, so it belongs there. However, like the weeping willow, it is fast growing, has roots which can disrupt foundations and sidewalks, and is short-lived. In fact, the USDA article mentioned above "no longer recommends this tree due to weak branch crotches, insect problems and fruit set." Since we are not plant pathologists and couldn't hope to diagnose or recommend treatment at this distance, we suggest you contact the University of Minnesota Extension Office for Scott County. They may recommend you have it looked at by a trained and licensed arborist, if you feel the tree is worth saving. 

From the Native Plant Image Gallery:

Fraxinus pennsylvanica

Fraxinus pennsylvanica

Fraxinus pennsylvanica

Fraxinus pennsylvanica



More Diseases and Disorders Questions

Young oak damaged by falling tree from San Diego TX
June 27, 2012 - My neighbor's Palo Blanco tree was struck by lightning and fell over our fence and on to a young oak tree in our yard. We waited a few days to see if the neighbor would offer help, but he never did,...
view the full question and answer

Pruning live oak shoots from San Antonio
September 10, 2011 - I am new to TX and am curious about removing suckers/water sprouts from my Live Oaks. Everything I've read about pruning Live Oaks states that you must paint ALL cuts, so I assume that all means al...
view the full question and answer

Possible causes for plant problems in East Texas
September 06, 2007 - I have been an avid gardener for over 35 years in Texas.I love the wildflowers and use them extensively in my 2 acre plot here in East Texas. There is something really bad going on with my garden: pl...
view the full question and answer

Leaves wrinkling on Tecoma stans from San Antonio TX
August 16, 2013 - My two year old esperanza (planted in the ground) froze back last winter, came back from the roots & has been doing well all summer. Recently one branch has leaves that are nice & green but very wrin...
view the full question and answer

Problems with Copper Canyon Daisy from Austin
June 08, 2014 - We had 3 copper canyon daisies. Two of them bloomed profusely last year, but only one has come back this spring. We cut them all back as instructed. When it was clear that two were not coming back, we...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2015 Lady Bird Johnson Wildflower Center