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?


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
Not Yet Rated

Friday - May 29, 2009

From: Livingston, NJ
Region: Mid-Atlantic
Topic: Non-Natives, Pruning, Trees
Title: Pruning smoketree in New Jersey
Answered by: Barbara Medford


How far from ground level do I prune a relatively young Smoke tree to get the bush effect?


This is a classic example of really needing the Latin name for a plant, because common names can be given to totally different plants in different places. We started out by looking in our Native Plant Database for "smoke tree" or "smoketree." First, we looked at  Cotinus obovatus (American smoketree), which, of course, in Texas we call a "Texas Smoketree." This tree only occurs in a few Southern and Southwestern states and is not shown in the USDA Plant Profile as appearing in New Jersey at all. Next on the natives list was Psorothamnus spinosus (smoketree), which is hardy to USDA Zones 9 to 11, common to desert washes of southern part of California, Arizona and Baja California. Spiny, nearly leafless shrub or small tree and is also known under the synonym Dalea spinosa. Scratch that one. Not only is it really not an ornamental you would be interested in raising, but it would probably freeze to death by October in New Jersey.

Since those were the only two plants known by that common name in our database, we went Googling and found Cotinus coggygria, (Smoke tree) which is native to Southern Europe and Central China, and is hardy to Zone 5 or a protected spot in Zone 4. Since a non-native is out of our range of expertise, we found this  Floridata site which can give you more complete information. As it is in the same genus, Cotinus, as the native listed above, you would probably be safe in just letting it develop naturally. It actually would take pruning to keep it from appearing bush-like. They usually develop multiple trunks, with leafing no more than 2 feet above the soil. Refer to these Images for more guidelines on how the bush grows.

Cotinus obovatus

Cotinus obovatus

Psorothamnus spinosus

Psorothamnus spinosus



More Non-Natives Questions

Lilac bush roots dangerous to house foundations
August 06, 2008 - Are lilac bushes dangerous to the foundation of a house? There is a lovely white-blooming lilac that grows against the house outside my bedroom window. My ex-husband said that the roots would destro...
view the full question and answer

Lantana failing to bloom from Tampa FL
October 04, 2012 - I reside in central Florida. I have planted several lantana the orange,red,yellow type. I don't have proper species name. They have been in the ground 3 weeks with 2" of potting soil around root ba...
view the full question and answer

Loss of leaves from globe willows in Utah
July 26, 2008 - I have four globe willows that have been in my back yard for the past 6 years. For the past month they have been losing their leaves from the bottom up. We had aphids in some of our other trees and ...
view the full question and answer

Replacing St. Augustine grass from Dallas TX
April 10, 2014 - Dear Mr. Pants, we are replacing dying St. Augustine grass in a small, sunny back yard with ground cover. What are your recommendations for a drought-tolerant evergreen ground cover? We will till a...
view the full question and answer

Disease on non-native French hollyhocks
April 16, 2008 - I live in Georgetown, Texas. I have some French hollyhocks that have some kind of disease on the leaves - I would like to know what to spray them with to get rid of it. It looks like brown blemishes...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2016 Lady Bird Johnson Wildflower Center