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

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

QUESTION:

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.

ANSWER:

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.

Aggie-Horticulture

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

Evergreen privacy hedge resistant to verticillium wilt
September 27, 2011 - I am looking for an evergreen, fast-growing privacy hedge (over 6') that is resistant to verticillium wilt and has low water requirements. I live in Monrovia, CA and have to replace hopseed bushes w...
view the full question and answer

Problems with non-native weeping willow from Hazlet NJ
July 03, 2013 - Leaves turning yellow on weeping willow planted in May. What causes this and how can I fix it? Mother's Day gift after SANDY uprooted huge tree.
view the full question and answer

Moth using Agarita as its larval food in New Braunfels, TX
March 27, 2009 - What moth uses agarita as its larval food? It is a perennial problem that can nearly defoliate the specimen and severely limit its flower production.
view the full question and answer

Leaves turning yellow on Banana Shrub in Eutaw. AL
July 28, 2013 - We have a very large (about 12' tall), very old (probably planted in the early 1900s) Banana Shrub in our front yard. It was very healthy until last year when its leaves began turning yellow and fal...
view the full question and answer

Why is my Mountain Laurel in distress?
November 26, 2008 - We have planted our 2nd Texas Mountain Laurel in the same spot (after fresh berm built with sandy loam) and it is not looking good in less than 2 weeks. We have an identical berm on the other end of...
view the full question and answer

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