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
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

QUESTION:

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

ANSWER:

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 Diseases and Disorders Questions

Should Mexican milkweed (Asclepias curassavica) not be used to attract Monarch butterflies?
November 20, 2015 - Should I remove Asclepias curassavica (Mexican milkweed) in my garden for threat of OE parasitic protozoan threat to Monarch butterflies? Is this threat as widespread as Chronicle implies? I had great...
view the full question and answer

Problems with a Cercis (Redbud)
August 25, 2014 - Half of my redbud tree is pooped out looking. On two places on the bark are areas where a few layers of bark have pulled back. In these areas there are white growths.
view the full question and answer

Yellow bands around edges of leaves in Whitney TX
July 20, 2009 - How can you tell whether esperanzas are getting too much water or not enough - ours have a small yellow band around the edges of the leaves - crape myrtles - same question
view the full question and answer

Loss of bloom on Fremontodendron californicum in California
June 11, 2009 - The flowers on my Flannel Bush all died at once I have noticed a sappy substance at the base of the trunk. There are still some flowers on bush but most are dead. It has been blooming since Feb. Is ...
view the full question and answer

Rose canker in roses on cedar posts
May 24, 2007 - While visiting the wildflower Center I saw that some of the plants were growing on trellis' made of posts cut from cedar trees. I made a trellis for my climbing rose bush and where the stems touched...
view the full question and answer

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