Rent Shop Volunteer Join

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
3 ratings

Thursday - June 26, 2008

From: San Antonio, TX
Region: Southwest
Topic: Invasive Plants, Non-Natives, Pruning, Trees
Title: Non-branching mimosa tree
Answered by: Barbara Medford

QUESTION:

I have a Mimosa Tree, just about 2 years old, grown from seed. The problem with it is that it has not branched out, it looks like one long branch growing out of the ground, about 5 feet if stood straight up. Is there anything I can do to shape like a normal Mimosa Tree?

ANSWER:

There are mimosas and mimosas. Two native trees that are called mimosas are Mimosa texana (Texas mimosa) and Desmanthus illinoensis (Illinois bundleflower). However, we're betting the one you refer to is Albizia julibrissi, a non-native of North America, instead native to an area ranging from Iran to Japan. All three are in the Fabaceae or pea family,but there the resemblance ends. At the Lady Bird Johnson Wildflower Center, we promote the use of plants native to North America because they need less fertilizer, water and maintenance growing in their natural habitats, and thus are better for the environment. The problem we had in trying to find the answer to your question is that most websites were more interested in getting rid of the mimosa than getting it to grow normally.

Plant Conservation Alliance Least Wanted Silk Tree.

USDA Forest Service Albizia julibrissin. The USDA Forest Service is usually at least neutral about non-natives but it doesn't have much good to say, and no information on how to make a single trunk branch.

But you didn't ask us to evaluate the value of your tree; you asked how to make it branch. Ordinarily, we would recommend pruning just below a bud area to promote growth of new branches. However, what you have now is a single leader, and most experts strongly advise against pruning leaders. You shouldn't even consider pruning now, in the heat of the summer, but wait until winter has cleaned off the foliage and permitted you to see the skeleton of the tree. By then, perhaps you will be able to see a branch radiating out from the leader that would make an acceptable crotch for the tree. This article from the University of Minnesota Extension on Pruning Trees and Shrubs seems to us to have the best diagrams and instructions for dealing with a young tree. You need to be aware that the mimosa is basically a weak tree, and a storm or even a strong wind could snap that thin leader in two. If that happens, we would advise you to start over with a stronger, native tree.

 

More Pruning Questions

How can I prune my Texas Mountain Laurels to be more tree-like?
March 24, 2011 - I planted several Texas Mountain Laurels last spring and would like to train them to be more tree-like rather than shrub-like. Each is around 36" tall with 5-10 trunks coming from the ground. Where...
view the full question and answer

Smarty Plants on pruning Clematis
August 26, 2005 - I would like to know about pruning clematis. The one I have is getting very large. Should I cut it back, and if so, in the Spring or Fall? I live in Michigan. Thank you.
view the full question and answer

Need information about pruning Persimmon trees in Buda, TX.
November 29, 2010 - Mr. Smarty, We have many wild persimmon trees in our yard. Some I want prune to bush size. What is the best way to prune these trees and to what extent can they be safely pruned. Thank you for shari...
view the full question and answer

Optimal time for trimming Fall asters
July 04, 2014 - RE: fall asters What is the latest date in the summer that I can trim my fall asters and still get a good amount of blooms in October?
view the full question and answer

Care for some non-native salvias from Austin
November 12, 2012 - Mexican bush sage and Salvia "indigo spires" are both blooming in my Austin beds right now. Once they stop blooming and/or frost gets them, could you tell me by how much they should be cut back? R...
view the full question and answer

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