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
2 ratings

Tuesday - November 27, 2007

From: Round Rock, TX
Region: Southwest
Topic: Pruning, Trees
Title: Mimosa shape
Answered by: Barbara Medford

QUESTION:

I planted a summer chocolate mimosa, and although it has bloomed lovely foliage, it has two main branches growing in a vee shape. Is this normal? Do I need to do anything to spur the growth in a more upright manner?

ANSWER:

The first thing we do when we are asked about a specific plant is check to see if it is a native of North America. We do this by searching on our Native Plant Database. At the Lady Bird Johnson Wildflower Center we are dedicated to encouraging the use and preservation of plants native to North America and, more especially, native or well adapted to the area in which they are being grown.

First the good news: Desmanthus illinoensis (Illinois bundleflower) , also called a mimosa, is a native of North America and does appear on the Edwards Plateau. Now, the bad news: The Albizia julibrissin, c. "Summer Chocolate" isn't it. Both are legumes, members of the Fabaceae family, but the native is a shrub, and what is commonly referred to as a mimosa or silk tree is a relatively small, fast growing tree. The mimosa tree is a native of southern and eastern Asia and the burgundy-leaved cultivar "Summer Chocolate" was recently developed in Japan.

So, we'll just talk about mimosas, in general, because the culture of the "Summer Chocolate" seems to be no different from that of other mimosas. It has a beautiful burgundy leaf, turning that color after a green spring. In answer to your question about the "V" shape, yes, this is fairly common. Not necessarily a good thing, but common. The mimosa often, but not always, develops multiple trunks. Trimming off the smaller of the two branches or trunks would not solve your problem and would only leave the tree lopsided. The mimosa has tender bark which is easily damaged, but it requires pruning to help develop a strong structure. It is susceptible to breakage either at the crotch due to poor collar formation or because the wood itself is weak and tends to break. Pruning excess top growth, evenly on both trunks would help to lighten the load while the trunks increase in girth with growth and perhaps become less liable to snap. This is the right time of year to be pruning, while the tree is semi-dormant. Mimosa trees tend to develop a draping, hanging shape, with stems growing toward the ground. These are good candidates for pruning, as that is extra weight and unbalance pulling on the crotch of the tree. Don't prune off more than a third of the top growth, concentrating on shape and relieving the strain on the crotch. For more information on the mimosa, see this University of Florida Extension website for details on culture, disease, etc.

 

 

More Trees Questions

Selection of native trees to replace trees lost in hurricane
September 28, 2008 - Hello, I have a tree replacement list I must choose from as I live in a HOA deeded area. I lost 2 pines to the hurricane. And according to them I need to replace with 2 large trees. The pines were 15 ...
view the full question and answer

Landscaping with water garden from Pendleton SC
August 15, 2012 - Searching for native plants in SC. Your results miss some plants listed on your site. I noticed this reading the Mr. Smarty Plants response to "Edible Plants for North GA" We aren't far apart. ...
view the full question and answer

Black walnut herbivory
June 13, 2005 - We moved to Texas just about a year ago and have loved it here. This past January we visited the Wildflower Center and obtained some black walnut seeds. Up until last night the tree was doing well p...
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

Pruning native Senna lindheimeriana
September 28, 2008 - I asked a question about pruning a Texas Senna tree. The Texas Senna I have is either a S. wislizenii or a S.lindheimeriana. It is a beautiful tree that I purchased at a Texas Native Plant nursery. ...
view the full question and answer

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