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?


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 - September 09, 2010

From: Driftwood, TX
Region: Southwest
Topic: Diseases and Disorders, Pruning, Trees
Title: When is the best time to trim oak trees in Driftwood TX?
Answered by: Jimmy Mills


When is the best time to trim oak trees?


This is kind of like a word association game: you say "black", I say "white"; you say "night", I say "day"; you say "trim oak trees", I say "oak wilt". This is because oak wilt is one of the most destructive tree diseases in the United States and is killing oak trees in Central Texas in epidemic proportions. It is an infectious disease caused by the fungus Ceratocyctis fagacearum which invades and disables the water-conducting system in susceptible trees. Oakwilt is spread by tiny wood boring beetles called nitidulid beetles that are attracted to the sap of oak trees. Fresh wounds in oaks draw these beetles like honey draws flies. The adult beetles carry spores of the infecting fungus on their bodies as they go from tree to tree and thus spread the disease.

Does this mean you can never trim you oak trees? No, but as in a lot of things, timing is everything. And, all species of oaks are not equaly susceptible to oak wilt. The nitidulid beeltes are least active in very cold weather and very hot weather, ie. in mid-winter and mid-summer (like right now). 

Mr. Smarty Plants suggests reading the material from the Texas Oak Wilt Information Partnership and the Texas Forest Service to become more knowledgable about oak wilt and the care of your oak trees. This article from  the USDA  is very extensive, and tells you more about oak wilt than you probably want to know. It is well-illustrated.

The Texas Forest Service also has an online article How to Prune Trees that should be helpful.


More Diseases and Disorders Questions

Cedar trees dying in CO
July 18, 2011 - We have mature cedar trees at the home we bought in SW Colorado. The large ones have begun to die. Can too much water kill a cedar tree and is there anything I can do to keep them alive?
view the full question and answer

School project on acid rain effects on plants from Austin
October 18, 2013 - Hi I go to an Austin high school and I am doing a project on how acid rain affects plant growth. I am wondering if you know any plants that would be more or less susceptible to acid rain for this proj...
view the full question and answer

Burning sulfur over coals in the home for insect control.
July 18, 2008 - Is burning sulfur(over hot coals) in your home a safe way of getting rid of ants and insects?
view the full question and answer

Problems with October Glory maple tree in Evansville IN
June 10, 2010 - We have a 15 yr. old October Glory maple tree. 2 years ago we had a bad ice storm and this tree was covered with 1/2 to 3/4 " of ice. The tree resembled a chicken wishbone with its limbs touching ...
view the full question and answer

Getting rid of algae on dirt and patio
January 12, 2011 - Algae and on patio and dirt, and how to get rid of same?
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2015 Lady Bird Johnson Wildflower Center