En EspaŅol

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
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.
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

Would like fast growing evergreen trees in Austin, TX.
October 31, 2012 - Hi, We're moving to Southwest Austin and would like to plant a cluster of pines (or cypress trees?) or other fast growing, large and tall evergreen trees. Any suggestions?
view the full question and answer

What grows in Tampa FL
July 01, 2013 - Please let me know what grows in the backyard in Tampa, FL to provide screening and privacy?
view the full question and answer

When is the best time to trim oak trees in Driftwood TX?
September 09, 2010 - When is the best time to trim oak trees?
view the full question and answer

Tree with taproot for Jodhpur India
July 05, 2013 - I am a resident of India. I need information of a tree with tap roots to grow in my backyard. We have moderate to hot climate here. It needs to be as small as possible due to lack of space. It'd be g...
view the full question and answer

Pests on Fan Tex Ash
July 30, 2015 - We planted a Fan Tex Ash last year on our property. It's doing very well, but there are a lot of large stink bugs, yellow jackets and red wasps on it daily. We cannot seem to find any information on ...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2015 Lady Bird Johnson Wildflower Center