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

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

Trees for a privacy barrier
October 06, 2007 - What would you suggest to plant for a privacy barrier along a back fence in Austin Texas? They need to be hardy and atleast 10 to 12 feet tall to block my neighbor's second story view of my yard.
view the full question and answer

Trees for privacy and filtering dust in NY
March 23, 2011 - I live on a very busy, DUSTY, dirt road in Putnam County NY. (zip code 10524) What is the best, fast growing evergreen that I can use for dust control and privacy? I would prefer something that requi...
view the full question and answer

Sticky stuff dripping from non-native crape myrtle in Austin
August 01, 2012 - There is sticky sap-like stuff dropping from the very large crepe myrtle in my yard. The tree has quit blooming. This didn't happen last year when it was so dry; it started after we had all the rain ...
view the full question and answer

Need plants to provide a privacy screen in Cedar Creek, TX
March 31, 2015 - We need to screen out neighbor's house. What can we plant (fast growing tree or hedge) in partial shade? Area is dry in summer, but does get soggy during heavy rain. We live east of Austin in Cedar C...
view the full question and answer

Changing color of crape myrtle blooms
July 08, 2008 - I have 5 well established crape myrtle trees whose blooms are a very light lavender/pink color. I would like to know if there is any way to deepen or change the color of the blooms. I would prefer a m...
view the full question and answer

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