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

Tuesday - September 12, 2006

From: Pasadena, MD
Region: Mid-Atlantic
Topic: Diseases and Disorders, Trees
Title: Yellowing of Thuja occidentalis leaves in early Fall in Maryland
Answered by: Joe Marcus


Mr. Smarty Plants, I am from Maryland. Please help. I have planted 23 Thuja occidentalis Smaragd in my front yard a few months ago. Height of about 3 feet. Most of the trees have turned golden brown. Are they dead? or is that normal. What did I do wrong? They are suppose to be evergreens. Thanks Bonita


Thuja occidentalis or arborvitae is an evergreen species. While it is normal of arborvitae - especially certain cultivars - to turn reddish-yellow during winter months, it is not normal for that to happen this time of year.

Some possible causes for your plants' condition are water stress (too much or too little), root disease which is usually related to watering issues, transplant shock, leaf miners or mites. From your description of your plants we would say that leaf miners and mites are not the likely culprits, but we can't rule them out. More likely, there is some issue involved in the transplanting and acclimation process that caused you plants to turn brown.

You should talk to your local nurseryman, arborist or cooperative extension service about the problem as someone may need to actually see your plants to give you a proper diagnosis. You are fortunate in the state of Maryland to have an excellent cooperative extension service. Their really nice Home and Garden Information Center website provides information for investigating plant problems.


More Trees Questions

Thorn bushes for a fence in Puerto Rico
November 17, 2015 - I'm looking for thorn bushes that grow in Puerto Rico. Want to use as fence to keep wild life in. Thanks, at least 5 ft tall so dogs can't get out.
view the full question and answer

Junipers for restoring area in Bulverde TX
November 03, 2012 - Are ashe or virginiana junipers for sale around the hill country? I would like to recreate the natural plant life that was bulldozed next to my home. Do you recommend any other types of juniper that ...
view the full question and answer

Shade tree for Southern California
November 14, 2013 - I had to cut down my huge ficus tree for several reasons, however it provided lots of shade, that we miss. Can you help me find a good shade tree with non-invasive roots that is good for growing and p...
view the full question and answer

Need suggestions for trees to withstand high winds on Top Sail Island, North Caroloina.
August 20, 2013 - Moving to coastal southern North Carolina. Planting native trees and shrubs, wax bayberry, Redbud, love the River Birch. What type of tree has the deepest roots or would be least likely to blow over...
view the full question and answer

Looking for an evergreen vine to grow on trellis as a privacy screen
July 11, 2015 - Hello, I'm looking for an evergreen vine to grow on a free standing trellis. It is used as a screen on our back porch, so ideally we would not like to use anything that flowers due to the insects ...
view the full question and answer

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