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?

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 - 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

Leaves falling off live oak tree in Eureka TX
August 22, 2009 - I have the same question; it is in Navarro County in August. The leaves are falling off my live oak tree, they are brownish yellow, but it is not oak wilt. What might it be? This year I put mulch arou...
view the full question and answer

Sap flowing from live oak trees in Austin
May 08, 2010 - I have live oak trees in my backyard,17 to be exact. I live in Northwest Austin, in Williamson county. There are two live oaks growing about 4-5 feet apart in the center of my yard. One appears to ha...
view the full question and answer

A good Amelanchier (Serviceberry) for Brooklyn, NY.
November 03, 2015 - I am looking to purchase an Amelanchier to plant in Brooklyn this month. Would you know which variety works best in a small garden and also is it too late to plant. Mainly, I am looking for someone wh...
view the full question and answer

Brown spots on young redbuds in Lincoln TX
August 01, 2010 - I have lined my driveway in Lee County Texas with Red bud trees purchased both in Dripping Springs and in College Station. The 14 trees are of varying ages and heights (planted during the fall and wi...
view the full question and answer

When is the appropriate time to prune pecan trees in Hewitt?
September 07, 2008 - Labor Day Weekend my husband decided to trim all the low branches on a big pecan tree in our back yard which I thought should had been done at the first of the year, our temprature is in the mid 90's...
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