En Español

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
4 ratings

Tuesday - May 04, 2010

From: Dallas, TX
Region: Southwest
Topic: Pruning, Soils, Watering, Trees
Title: Problems with Texas Mountain Laurel in Dallas
Answered by: Barbara Medford

QUESTION:

I have a Texas Mountain Laurel that is about 3 years old. When I bought it 2 summers ago, it was about a foot high. Now it is over 6 feet. It seems to have grown so fast that the branches can't keep up. After about 2 feet from the bottom, they are green and limp. It can't hold itself up. It's lying on the ground. I've tied it up to pole supports but I just don't know if that's the best thing for it. It looks so bunched up now. I'd like to train it to be a multi-trunk tree similar to crape myrtles. What can I do to help this guy out?

ANSWER:

We will have to say we have never been presented with exactly this set of symptoms from a Sophora secundiflora (Texas mountain-laurel) before, and we sure don't know what is causing them. Let's begin with the basics. According to this USDA Plant Profile, the Texas Mountain Laurel does not grow in North Central Texas, including Dallas County. Obviously, you can buy anything and plant it anywhere, but that doesn't mean it's going to be happy there. It is a lush, evergreen plant with its fragrant purple flowers that seems like it should be a tropical plant from a rain forest. Not. This is a desert plant, accustomed to surviving, blooming and propagating itself without human intervention in sometimes harsh conditions. From our Native Plant Database, here is the Soil Description preferred by this plant.

"Brushy slopes; open plains. Common in limestone soils. Well-drained sand, loam, clay, caliche, limestone."

The same source indicates it likes a highly alkaline soil, dry conditions and sun or part shade. It absolutely requires good drainage in the soil. Frankly, we think you are loving your Mountain Laurel to death. It grew so well, it can't support itself. It is ordinarily a slow-growing plant, partly because it must adapt to desert conditions just to survive. 

Here's our prescription, we have no idea if this will work, and if the tree dies, it may be because it is already dying. First, and foremost, NO FERTILIZER! ever. Trees planted where they belong subsist on the soils they are acclimated to by millions of years of experience, and this is a plant that particularly does not like fertilizer. Second, cut out the watering. If your tree is in range of an automatic sprinkler, try to reset the sprayers or in some other way lower the amount of water it is receiving. Now, check the drainage of the soil. Is the tree in a "tree well?" Bad news. Water will collect in that, whether or not it drains well. Since most of your area has heavy clay soils, that tree's roots may be drowning. Your area has had more rain than normal the past few months, which isn't helping. Correcting drainage for a tree already in the ground for 3 years is almost impossible. Again, cut down on the water that gets to it, keep the roots mulched with a good shredded hardwood mulch to help soak up some of that water. As that mulch decomposes, it should begin to improve the texture and drainage of the soil. Use continued applications as the level of the mulch lowers to very gradually raise the soil level.

The only other suggestion we can make, because that tree should NOT be lying on the ground, is to trim some of the upper foliage. Treat it like you would transplant shock (which still could be a contributing cause even after 3 years) and trim off about 1/3 of the upper portion of the plant. This will take some of the burden away from the roots of supplying water and nutrients to the upper leaves. If you still want to stake the plant, here are some instructions extracted from a This Old House website:

"Once you straighten a tree, it's a good idea to stake it. Drive a couple of wood stakes on the side of each tree. Then run wire or rope from the stakes and wrap it loosely around the trunk about two-thirds of the way up. To protect the bark against chafe, cover the wire or rope with scrap pieces of garden hose. You shouldn't let your trees become too attached to their stakes. Unstaked trees develop stronger root systems than those with artificial supports. So do your evergreens a favor and take the stakes out next spring."

As for training the tree to be multi-trunk, you can see from the pictures below that they naturally put out more than one trunk. We think your tree will do that once it becomes stronger and has the energy for something more than survival. You can train a tree to have a single leader by pruning away secondary trunks, so the only way to "train" it to be multi-trunk is to give some more trunks a chance to emerge. 

From our Native Plant Image Gallery:


Sophora secundiflora

Sophora secundiflora

Sophora secundiflora

Sophora secundiflora

 

 

 

More Trees Questions

Plant Suggestions for a Partly Sunny Steep Bank in Illinois
November 09, 2013 - I am looking to plant something on a steep clay bank on our Illinois property. It is on the edge of our dirt road with trees above the bank and is partly sunny. What would work best for that type of a...
view the full question and answer

American Beech with Brown Leaves
August 06, 2015 - I have a North American beech tree in Oregon. Its leaves started out with big brown spots on the leaves and is pretty much turning all the leaves on the tree brown. What could be causing this and wha...
view the full question and answer

Wispy plant to put behind a waterfall
May 30, 2008 - Needing a 10-20ft wispy ______ to plant behind our waterfall to help block out road noise. We live in Austin. I've looked at the Mexican weeping bamboo but are there other options?
view the full question and answer

Storm damage to native sweet bay magnolias in Kentucky
February 04, 2009 - Can you please share information on storm damage to sweet bay magnolias; if the top is broken off can the tree maintain its natural shape or will the sides begin to grow more than the top; i.e., growt...
view the full question and answer

Problems with a Sherman (Shumard?) Oak from Bixby OK
May 14, 2012 - We have done extensive research on oak fungi/diseases/pests could be affecting our Sherman Oak tree but we are stumped. The leaves are falling off and have some sort of moldy bunch within the leaf it...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | JOBS | SITEMAP | STAFF INTRANET
© 2016 Lady Bird Johnson Wildflower Center