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?

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
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 - October 23, 2008

From: Richmond, TX
Region: Southwest
Topic: Trees
Title: Knots growing on Arizona Ash in Richmond, TX
Answered by: Barbara Medford

QUESTION:

I have three Arizona Ash trees around my house the trunks are at least 15" in diameter. One of the three has at least 25 large knots growing on its trunk, some maybe 6-8" in size. What are they? Are they harmful to the tree? Thanks for your time and trouble.

ANSWER:

There are several things that can go wrong with Fraxinus velutina (velvet ash), including Texas root rot, nematodes, chlorosis, cankering, mildew, fungal infections and emerald ash borer. However, it sounds more like what your tree has is galls, which is ususually non-threatening to the tree, and involves a structure to protect larvae of some insect, most often wasps. When the galls show up, it's really too late to do anything about them, and they usually involve just one generation per year. See this article from the Kemper Center for Home Gardening Galls on Trees. It has suggestions for Integrated Pest Management, but just about all the information we could find on galls said it was nothing to really worry about. Most of the pictures we could find of galls were on oak trees, but they tend to be tree-specific, so something that likes to live on an ash may be causing the bumps on your tree. Look at these pictures of galls on trees to see if there are similarities to what your  trees are experiencing. 

Since we are not entomologists and, of course, cannot see your trees, we would suggest you contact the Texas A&M AgriLIFE Extension office for Fort Bend County.  This site has contact information and also an Horticulture link. They may recognize the symptoms and know what it is and whether you need to take any action about it. 

 

More Trees Questions

Quercus polymorpha or Mexican white oak
June 19, 2007 - On the Texas Oak Wilt Information Partnership website, they list a "Monterrey Oak" as one of the White Oaks (#3 in the FAQ section). I cannot find Monterrey Oak in your Explore Plants section; does...
view the full question and answer

Eliminating black locust volunteers in Rockville MD
September 27, 2011 - I am a landscape designer whose client has a very large, mature black locust in her front yard. Not surprisingly, she also has multitudes of black locust volunteers popping up all over her yard. The...
view the full question and answer

Problems with non-native indoor palm in Guilford CT
April 08, 2012 - My question is I have an indoor palm plant that I have had for 7 yrs. It has grown from about a 5" plant to about 3' tall plant. The past few weeks the leaves are turning yellow & brown and lost abo...
view the full question and answer

Chilopsis linearis Bubba in Hunt TX
October 18, 2009 - I purchased 3 desert willows (label: chilopsis linearis) to create an oasis area around a fountain which is in the center of my circle drive. But I need one more. Now I can only find the "chilopsis...
view the full question and answer

Would like suggestions for a tree or bush to be given as a memorial gift for friends in Austin, TX.
April 26, 2011 - Hello, I would like to give a memorial gift of a tree and/or bush native to the Austin area to friends living there. Any suggestions? Local vendors would be appreciated also. Thanks very much!
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP | STAFF
© 2016 Lady Bird Johnson Wildflower Center