Contact Us Host an Event 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

Thursday - April 09, 2009

From: Medina, OH
Region: Mid-Atlantic
Topic: Trees
Title: Browning of Red Western cedars in Medina, OH
Answered by: Barbara Medford

QUESTION:

I have a row of Red Western Cedars bordering my yard. One week after my lawn people but down spring fertilizer and grub control, they began turning brown. Is there any correlation? If not, what causes Red Westerns to have their branches turn brown? Thank you.

ANSWER:

Well, it would certainly arouse suspicions because of the time frame involved, wouldn't it? From our Native Plant Database, we learned that Thuja plicata (western red cedar), while native to North America (or it wouldn't be in our database) it is not native to Ohio. If you have had them for a while and they have been okay, the fact they are not native to your area is probably not the reason for the browning. 

So, we'll begin with the possibilities of the fertilizer and grub control. If the fertilizer was of the "weed and feed" type, and was sprayed around, that could very well be the source of the problem. "Weed and feed" fertilizer is specifically a lawn fertilizer. Grasses are monocots, and the weed killer in the fertilizer is aimed at dicots, or broad-leaved plants. So, what benefitted the grasses by killing off their competitors, the broad-leaved weeds in the lawn, could very well have done a lot of damage to the cedar. As for the grub control, we could find nothing about whether the ingredients in grub control were specifically a threat to plants, but, again, they contain certain toxic substances in order to kill the grubs, and if applied to tree foliage could likely cause trouble.

Other reasons for this browning? We learned that the western red cedar needs a moist, slightly acidic soil, but can adapt to a little more alkaline soil. It is susceptible to bagworm damage and heart rot, but neither are considered serious threats.

Conclusion? We don't have one. Again, the timing leads us to believe the spraying may be the cause. Whether or not the tree can recover, we don't know that, either. This is a valuable tree, and grows to be very large, but slowly. Give it some care, maybe some extra water, but not fertilizer, and hope that time will help the tree heal itself. Next time, either get a different landscaper or watch them closely. Untrained personnel often don't understand the consequences of what they are spraying around indiscriminately. 

Pictures of  Thuja plicata (western red cedar)

 

More Trees Questions

Plants for soil with basalt outcroppings in Idaho
March 30, 2008 - We have basalt (lava) outcropping in part of our back yard and know we'll have to search for pockets of soil in which to plant. Any suggestions about what trees or shrubs would have a chance in thes...
view the full question and answer

At what age does Possumhaw (Ilex decidua) begin to flower in Pflugerville, TX?
January 13, 2011 - At what age does a female possumhaw (Ilex decidua) usually bloom and set fruit? Or is there a way to identify the female other than by the presence of berries? I grew a number from seed and want to ...
view the full question and answer

Late leafing and early leaf-drop of Ohio buckeye tree
October 28, 2005 - We recently bought a house which has an ohio buckeye tree in the back yard. It stands about 40 feet from a large creek in Troy, Ohio. The tree is about 30 feet tall. A strip of the bark is missing....
view the full question and answer

Bignoniaceae Family Members Fix Nitrogen?
January 23, 2016 - Do plants in the Bignoniaceae family, such as Tecoma stans and Chilopsis linearis, fix nitrogen into the soil? I ask because they have a bean-type pod. Just curious.
view the full question and answer

Oak trees losing leaves in Longview, Texas
August 18, 2009 - One of my oak trees is losing its leaves (it is the first week in August). They are turning brown and falling at an alarming rate. The ground under this tree is covered, but my other trees seem unaffe...
view the full question and answer

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