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

Wednesday - June 20, 2012

From: New Braunfels, TX
Region: Southwest
Topic: Diseases and Disorders, Pruning, Trees
Title: Trimming oaks and elms from New Braunfels TX
Answered by: Barbara Medford

QUESTION:

I would like to trim my live oaks and elm trees at the same time, if possible. I think they are American Elms. When is the best time to do this and avoid oak wilt and Dutch elm disease? Should all cut branches be treated with tar or black spray paint?

ANSWER:

If you are bringing in professional licensed arborists to trim your trees at the same time, that is a good idea. If you are planning to have them trimmed before November, that is a bad idea. Sometimes woody shrubs with blooms can be trimmed at other times of the year to enhance blooming, but as a general rule planting and pruning should be done in cold weather when the plants are dormant.

The Live Oak is a very special case. You are definitely in the Oak Wilt danger area in Central Texas, which means touch-it-not until November at the earliest. We suggest that anyone caring for Live Oaks in this area go to oakwilt.org and read all the dos and don'ts of oak care. In answer to your question on painting cut areas, yes, we do recommend painting any cut area bigger around than your thumb with a paint specifically formulated for tree wounds. There is no cure for Oak Wilt, and prevention is the only way to go. The best prevention is to avoid any kind of wound to the oak bark, such as banging it with motorized equipment (lawn tractor) or cutting with a weedeater. Any break in the bark will result in exuding of sap, which will attract the nitidulid beetle, who loves the sap and may have the fungus that causes Oak Wilt on his body from an already diseased Live Oak from which he got his last snack.

On pruning Ulmus americana (American elm): Since you are particularly concerned about Dutch Elm Disease, we found this article from the USDA Forest Service on How To Save Dutch Elm Diseased Trees by Pruning. From eHow, here is an article on When to Prune Elm Trees. Frankly, we still think the best idea would be to bring in professionals with the know-how and right equipment and do the pruning all at once.

 

From the Image Gallery


Escarpment live oak
Quercus fusiformis

Escarpment live oak
Quercus fusiformis

Escarpment live oak
Quercus fusiformis

American elm
Ulmus americana

American elm
Ulmus americana

American elm
Ulmus americana

More Diseases and Disorders Questions

Recently planted Chinquapin Oak with browning leaves in Marlin, TX.
July 31, 2012 - We planted a Chinquapin Oak this in March 2012. As of July 21, 2012, the tips of the leaves on the lower branches are turning brown. We cannot see any insects. There does not appear to be any fungu...
view the full question and answer

Problems with mountain laurel from Sunrise Beach TX
August 29, 2012 - In Llano Co., TX near lake LBJ, crushed granite type soil - my 4 - 5 year old TX Mtn. Laurels (2), about the size of large wheel barrows, are turning very pale, dropping leaves and on 1 the seed pods ...
view the full question and answer

Discouraging Poison Ivy
June 27, 2015 - Is there a fern that discourages poison ivy from growing?
view the full question and answer

Texas Ash secreting sap in Lockhart, TX
July 05, 2012 - I have what I believe is a Texas Ash in my front yard that is secreting a sap with what looks like some wounds on it with some white stuff and with black and red looking ants as well as it has a lot o...
view the full question and answer

Non-native invasive carrot wood tree losing leaves in Alpine CA
April 22, 2014 - My carrot wood tree is losing all of its leaves. The tree is about 15foot high & 13 years old. Could it be gophers? The tree was trimmed 1 year ago.
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.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP | STAFF
© 2015 Lady Bird Johnson Wildflower Center