Host an Event Volunteer Join Tickets

Support the plant database you love!

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

Monday - March 28, 2005

From: Allentown, PA
Region: Northeast
Topic: Diseases and Disorders, Shrubs, Trees
Title: Smarty Plants on arborvitaes
Answered by: Joe Marcus

QUESTION:

Hello, I live in Allentown, PA and have a 7-foot arborvitae shrub in my backyard, planted in the corner of the yard where a wood fence intersects with the brick wall of the garage. I have had many plant species in that area so I assume that the soil is acceptably fertile. I softened the surrounding area where the hole was dug to ensure root penetration when I planted the shrub in Summer 2003 and the shrub gets significant water and has done well to this point. I have an identical arborvitae planted about 5 feet away. Recently I noticed that the leaves on back of the arborvitae that faces the wood fence/garage wall were all dried out and long dead. The front of the arborvitae seems perfectly fine, no discoloration, no loss of leaves; but the back is essentially bare after I finished pulling off all the dead leaves. While the identical species planted about 5 feet away does show small patches of dry dying leaves from time to time, overall it does fine. Any idea as to what this may be and how I can remedy it? Is this due to a lack of sunlight, a particular shrub disease, perhaps the cold winter? I've been told about 'nutrient spikes' that may help increase the nutrient intake. Are these recommended? It would be one thing if the entire shrub was drying out and dying, but its only a problem in the back of the shrub. Please help!

ANSWER:

Thank you for writing! The condition you describe sounds like winter injury, although there could be other causes as well. Here's what I think probably happened. Because your arborvitae is right next to a brick wall the conditions in the foliage of your plant within a few inches of the wall can be quite different than the conditions on the other side of the plant. Brick walls act as heat sinks, that is, they store heat on sunny days and radiate the stored heat at night or when it gets cloudy. The net effect for your arborvitae is that the foliage next to the wall probably did not acclimate to the colder conditions at the beginning of winter and was susceptible to freezing injury on the first really cold night of winter. If that night followed a sunny day, the effect would be especially pronounced. Very cold, very sunny days can have dramatic affects on even cold-hardy plants. Water stress at that time would exacerbate the problem. It is always a good idea to water your plants before a hard freeze if it occurs after a period of little or no rain.

There are some diseases that affect arborvitaes. Here is a link to a Penn State website with a very good section on Arborvitae Diseases. If you suspect a disease or insect problem I recommend taking a limb that includes both the affected area and some living tissue to your county extension agent for diagnosis.

I would not recommend using "nutrient spikes". In fact, you should never feed a stressed or diseased plant. It sounds like you have rich soil. Adding some compost when the plant begins to show new growth should be all your plant ever needs.

 

More Diseases and Disorders Questions

Freeze damage to non-native Philodendron selloeum in Deltona FL
June 22, 2010 - My philodendrons selloeum died this past winter in the freeze,came back slowly this spring and now are suffering with very small deformed leaves. Some do grow but are getting large brown dry areas on ...
view the full question and answer

Death of Texas Betony and Blackfoot Daisy from Austin
April 18, 2013 - I have one small area that there are two plants - Texas Betony and Blackfoot Daisy withered and died eventually. Same kinds of plants are doing fine close by. It is my front yard close to walk way.I w...
view the full question and answer

Pruning live oak shoots from San Antonio
September 10, 2011 - I am new to TX and am curious about removing suckers/water sprouts from my Live Oaks. Everything I've read about pruning Live Oaks states that you must paint ALL cuts, so I assume that all means al...
view the full question and answer

Brush cleaning fluid used under non- native Loropetalum in Roswell GA
September 25, 2010 - My painter cleaned their brushes under one of my Black Diamond Lorpetulum and it is wilting "BAD." Is there anything I can do?
view the full question and answer

Fungus Spots on Native Bush Honeysuckle
December 03, 2010 - My native bush honeysuckle plants that I have along my back fence have leaves that are turning yellow with spots. It appears to be a type of fungus, but not powdery mildew. Any suggestions as to what ...
view the full question and answer

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