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 - 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

Evergreen ornamental tree choice in northern Indiana
June 10, 2009 - Can you please advise on growing Lemon Cypress trees outdoors in zones 5/6 zip code 46311
view the full question and answer

Looking for juniper trees (Juniperus ashei) for sale
December 05, 2008 - Does anyone know anyone that sells Juniper trees in pots - the central Texas kind.
view the full question and answer

Old oak tree dropping leaves in Hazlet Township NJ
July 08, 2013 - I am 84 yrs old and have a 50 year old pin? oak. No more acorns, but the leaves are falling in clumps and are still alive. Every day I fill a huge garden bag with them. I live on a fixed income and...
view the full question and answer

Privacy screen for Sedona AZ
August 02, 2013 - I live In Sedona Az. A builder just built a house next to my house and the new house is ugly to look at. What plant or tree would grow fast and reach 18 foot in height fast. It can be about 5 to 6 foo...
view the full question and answer

Propogating snowbells from Elmendorf TX
June 06, 2012 - Is it possible to propagate Styrax platanifolius and Halesia diptera from cuttings? If yes, what is the process?
view the full question and answer

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