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

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

Plants dying in circular garden in Killeen, TX.
July 31, 2012 - I have a large circular garden in my backyard out in the country in Killeen Texas. Last year two elms died. This year the Rose of Sharon has been dying one by one. One bush will completely die off bef...
view the full question and answer

Treating scarred Gum Bumelia from Lampasas TX
June 05, 2013 - We have a very old Gum Bumelia with a scarred open tree trunk. In the past concrete was used to fill the scarred trunk. What is the acceptable method of helping the tree. More concrete or using blac...
view the full question and answer

Possible fungal infection of oak trees in Mastic Beach, NY.
June 19, 2012 - Sir, I have a yard full of HUGE Oaks. The one in question is about 80' tall 48" in diameter at the base. They are all well maintained fed and trimed and elevated every 3 or 4 years. About 4 years a...
view the full question and answer

Mystery pest eating portulaca blooms
July 02, 2006 - I'm from Texas and I purchased some portulaca from a local nursery about three weeks ago and planted them in the front yard....with plenty of sun. Here's the problem. The foliage seems very health...
view the full question and answer

Spots on just-emerging Zexmenia in Austin
April 02, 2010 - My zexmenia is just coming up from the ground after a cold winter in Austin. The leaves are all spotted with tiny holes as if something is munching on them before they even leave the ground or just as...
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
© 2015 Lady Bird Johnson Wildflower Center