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
1 rating

Tuesday - February 10, 2009

From: Austin, TX
Region: Southwest
Topic: Trees
Title: Encouraging branch growth of live oak trees in Austin
Answered by: Barbara Medford

QUESTION:

I recently had an elm tree cut down that was crowding out 2 live oak trees in my front yard. The oaks have no branches on the sides that were next to the elm. The elm stump is still there. I need to know what I can do to help the live oaks grow out where they have been crowded. Should I remove the stump? (I would like to avoid that) What kind of fertilizer should I use on the oaks and when should I put it out? The oaks need trimming, would this help stimulate growth?

ANSWER:

First of all, removing that elm stump, if it involved a stump grinder, would almost inevitably hurt the live oaks, not a good idea. So, if you're willing to live with the stump, we think that's fine. You do need to keep your eye out for elm sprouts, as that tree is going to be fighting for its life, with seedlings popping up and suckers coming off the stump and roots. Keep cutting them back or yanking them out and they will finally give up. And don't put herbicide on any of the elm tree remains, either, as it could manage to get in the soil and damage the live oaks.

Now, in answer to your question. Yes, some new growth will come in on the formerly crowded side of the live oaks. It won't be a quick process, but at least it will get better. But don't, repeat, do not trim the live oak now. We are now into February and the Nitidulid beetles will be active from now through May. Oak Wilt, a dread scourge of oak trees, and especially live oaks, is caused by a fungus introduced into the trees by the beetles. Cuts or wounds in the tree may offer an opportunity to those beetles. It would be a shame to go to all that trouble to encourage the live oaks, only to have them succumb to oak wilt. The safest thing to do is take good care of the oaks, making sure they are getting plenty of water, and wait until a cold spell in January to do a little shaping up, taking some off the side that was able to grow. Don't take off too much at once, do it gradually, until you get to the point where the sides match up a little better. The tree needs the nutrition those leaves are providing, and if you cut off too much at once, it could be seriously stressed out. At this point, we don't feel fertilizer is an especially good idea. Those trees have been getting along just fine with the native soil around here for millions of years without any human intervention. It might be a good idea to mulch the roots with a good shredded hardwood mulch, to help hold in water and protect the roots and soil from the heat. 

And don't forget-watch out for little elm trees trying to regain their place!

 

More Trees Questions

Probably non-native crapemyrtle trees damaged by hurricane
January 15, 2009 - I have 5 crape myrtle trees. I live in Galveston, Tx and when Hurricane Ike came through in September the salt water I think killed them. They have not come back since then and are brown with no leave...
view the full question and answer

Large shrub or tree for front door in Houston
January 16, 2013 - I am in search of a shrub or tree to plant next to my front door. I want a showy medium sized shrub or tree (8 to 12 ft), decorative, and a privacy screen since my front door faces my next door neig...
view the full question and answer

Pruning Live Oak trees to limit height.
June 08, 2015 - I notice many of my neighbors here in Katy (Fort Bend county) would have landscapers cut the lower limbs/branches of the live oak trees in their front yards, and the trees naturally keep getting talle...
view the full question and answer

Black Walnut tree in LA
March 12, 2012 - I was just given a black walnut tree and am trying to determine where to place it. I’ve read on your site that “Certain plants will not grow under Black Walnut trees because of the juglones that the ...
view the full question and answer

Sap of mulberry similar to sap of maple for syrup from Wellman IA
February 23, 2012 - Can the the sap of the mulberry tree be used to make syrup similar to maple Syrup?
view the full question and answer

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