En Español

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

Friday - February 24, 2012

From: Bethesda, MD
Region: Mid-Atlantic
Topic: Non-Natives, Poisonous Plants, Shrubs
Title: Problems with shrubs by pool in Bethesda, MD
Answered by: Barbara Medford

QUESTION:

We are trying to grow Otto Luyken Laurels by a pool and doing okay, some brown spots on leaves, but not many. Also have Arbivatea beside the pool about 3 feet from the edge of the pool. They have a lot of internal dying near the trunk. The rest of the leaf looks ok, but have some tip browning as well. 1 or 2 have some dead branching at the bottom. Do Arbivatea and Laurels do okay at a pool side? What nutrients should I give them to overcome the effects of salt water?

ANSWER:

Did you mean "arborvitae" instead of "Arbivatea" as we could find nothing on the second name anywhere, in or out of our Native Plant Database. There is, however, Thuja occidentalis (Arborvitae), which is native to Maryland, and we hope that is your shrub.

There are a number of plants with "laurel" in their common names that are native to North America, which is the area of interest for the Lady Bird Johnson Wildflower Center and Mr. Smarty Plants. However, apparently what you have is Prunus laurocerasus 'Otto Luyken,' which is native to southwestern Asia and southeastern Europe. It is sometimes referred to as "cherry laurel" or "English laurel." There are a number of shrubs native to North America with "laurel" as part of their common names, but Prunus caroliniana (Cherry laurel) is the only one that is also a member of the Prunus genus.

WARNING: The seeds, twigs, and leaves of all Prunus species contain hydrocyanic acid and should never be eaten.

Without knowing the full situation in your poolside garden; i.e., how much sun does the area get, how much of the shrub roots are paved over, etc. it is hard for us to make any judgment on the brown spots or the internal dying of branches. We did find this article on Brown Spots on Leaves that has several links with pictures that might help you diagnose that problem.

Since the arborvitae is native to North America, we will start with what information we can find on it. From Ohio State University, here is an article on Thuja Occidentalis. From that, we have extracted this information on "Foliage."

Foliage

  • sprays of scale-like, dark green, miniature leaves are evergreen and held so tightly against the stems that the young twigs are often completely hidden
  • old foliage from the self-shaded middle of the shrub abscises noticeably in Autumn, and falls through the interior of the canopy directly to the ground below, forming a light brown carpet that is easily raked up
  • the remaining foliage on most of the cultivars turns to an unnattractive chartreuse-brown in the coldest portions of Winter, but thankfully returns to medium- or dark green by late March

As we read up on this plant, we learned that it can get very large, and is somewhat messy, dropping needles and cones. Perhaps it might be a little large for a pool environment.

Prunus laurocerasus is not in our Native Plant Database, so we have looked at this Virginia Tech article on it, from which we have extracted this line:

"Cherrylaurel is a good plant to use near the ocean because of its tolerance to salt spray."

That is as near as we have come on either plant on toleration of salt-filtered pool water. So, we will look a little further at salt water pools, with which we are not familiar, and see if we can get any more clues. We found this article from Dave's Garden, Tips for Planting Around the Pool, which included this statement:

"However, unless you put an inordinate amount of chlorine and other chemicals in your pool, the amount of damage caused by treated water splashing on your plants will be minimal. Same goes for salt water system pools."

 

 

 

 

 

 

More Non-Natives Questions

Eliminating straggler daisy from St. Augustine grass in Hochheim TX
May 14, 2010 - I have straggler daisy in my St. Augustine grass. What herbicides work well on straggler daisy and won't ding up the grass too bad?
view the full question and answer

Will corn fall victim to allelopathy from hackberry in Clarkridge AR
March 30, 2013 - Will my corn be inhibited by a nearby hackberry and if so would it help to cut it down? I understand that sometimes the soil is full of the chemicals the tree produces.
view the full question and answer

Problems with non-native Pink Jasmine from Austin
March 23, 2011 - A week or so ago, I purchased two beautiful pink jasmine vines. The first few days after planting, they did wonderful. Now, some leaves and stems are turning brown and some flowers have fallen off. ...
view the full question and answer

Powdery growth in hydrangea in Philadelphia
June 20, 2010 - My hydrangea plants have a weird growth on their leaves that looks like white rice. It looks like it would be powdery if brushed, but I don't want to touch it for fear that it some type of mold. Any...
view the full question and answer

Identification of Cryptomeria japonica for homeowners association
May 09, 2007 - Good morning. We are wondering if Cryptomeria japonica trees can fit under the term "pine like". We used the term pine like when asking for our home owners associations approval and we put in a Cr...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | JOBS | SITEMAP | STAFF INTRANET
© 2016 Lady Bird Johnson Wildflower Center