Explore Plants

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
    
 

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
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

Pruning Bald Cypress in Wylie, TX
January 02, 2010 - I have a 6 year old bald cypress that sustained damage to the upper portion of its trunk a couple of years ago. Since that time it has grown more outward than upward and developed a rounder shape. I...
view the full question and answer

Should I use wound paint when pruning my live oak tree?
February 04, 2010 - When trimming live oak branches, is it best to coat the wound on the tree? I have been doing this but have recently heard that it can actually be bad for the tree.
view the full question and answer

Avoiding cedar elm because of allergens
August 18, 2008 - Hi. Cedar elm, Ulmus crassifolia, seems like a wonderful, tough, drought tolerant native tree. I'd like to plant several to shade buildings. I'm being discouraged from doing so because Cedar elm ...
view the full question and answer

Evergreen plants safe for horses in Louisville, Kentucky
May 16, 2010 - I have a horse farm in Louisville, Ky. I want to plant evergreen plants along the walls in front of the horse barns. What types of plants are not toxic to horses can I use? Thank you so much for all y...
view the full question and answer

Freeze damage to Mexican olive in Austin
December 13, 2009 - I have a Mexican Olive tree/bush. It is young - about 8 ft. tall. This last freeze in Austin made many of its leaves turn black. I got this from your database: "Its native range extends no farther...
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.