En Español

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

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

Thursday - March 18, 2010

From: flagstaff, AZ
Region: Southwest
Topic: Diseases and Disorders
Title: Need help with canker in willows in Flagstaff, AZ.
Answered by: Jimmy Mills


We've got a lot of willows in high altitude desert conditions, irrigated. They've got canker and I want to know if there's anything I can paint on the pruning wounds when I go around trying to remove infected branches. otherwise I'm afraid of the pruning wounds just being new avenues for infection.


You don't mention the kind of willows that you have (there are 55 species of Salix in our NPIN Data Base), but many seem prone to having canker problems.

Lets look at the pruning paint question first, and then I'll provide some links that might helpful in dealing with the canker problem.

In the past, applying pruning paint to pruned branches was generally thought to be necessary to prevent infectious diseases and infestation by insects. The current thought is that in most cases it is not necessary, and that it may cause more harm than good. Here are a couple of links that support that idea.


Tyler Trees

This Bulletin from the  Integrated Pest Management Program of the University of Illinois Extension, and this report from the University of Florida have some good information about canker in willows and the fungus that causes it.



More Diseases and Disorders Questions

Leaf problems on oaks in North Liberty IA
June 12, 2010 - My oak trees (young and old) are showing leaf problems. Is there a disease or insect causing oak tree disease?
view the full question and answer

Why did my Prairie Flax plant die in Austin, TX?
April 27, 2012 - Hello, We planted 4 prairie flax last fall in garden. They were all growing nicely until last month when I found that one of them has completely dried up and died. The plants are planted together a...
view the full question and answer

Transplant shock in Achillea millefolium
May 28, 2007 - I had a clump of yarrow in my garden and was worried that it would become very aggressive to the other plants. I decided to transplant it into large clay pots to control it. Immediately after the tran...
view the full question and answer

Fungal root rot in non-native Shasta daisies in Channahon IL
July 21, 2009 - HELP! My Shasta daisies have fungal root rot. Is there any way to save them? I've been removing the browned stems. I'm so sad.
view the full question and answer

Problems with spreading juniper in Sturgis, SD
May 25, 2011 - I live in Sturgis, South Dakota and I have two different varieties of Spreading Juniper in the yard as ground cover. They have developed an orange colored fungus that goes dormant in the winter but a...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2016 Lady Bird Johnson Wildflower Center