En EspaŅol

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
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.
Need help with plant identification, visit the plant identification page.
 
rate this answer
Not Yet Rated

Tuesday - September 27, 2011

From: Austin, TX
Region: Southwest
Topic: Transplants, Watering, Shrubs
Title: Has overwatering harmed cherry laurels in Austin?
Answered by: Barbara Medford

QUESTION:

I am so upset. I know we've been having a terrible drought this year in Austin, and I've been trying to balance water conservation with protecting our recent very large investment for massive landscaping at our new construction. We did plant all non-invasives, mostly native. Our two 5' tall Cherry Laurels have been doing ok in a part shade/part sun raised bed at the east-facing end of our patio - but all plants are taking a beating these days. Friday I treated them to an extra long gentle soaking. Today (Sunday) I went to visit with them and was astonished that the vast majority of leaves have turned brown. Almost overnight! Coincidence? Or did I shock them when I gave them that soaking? THANKS for any insight!

ANSWER:

Begin by following this link, Prunus caroliniana (Cherry laurel), to learn what this plant ordinarily requires in terms of shade and watering.

When we are spending so much time answering questions on what to do about the drought, we were a little slow to grasp that over-watering could cause a result very similar to under-watering. To our surprise, searching on the Internet yielded a number of references on the subject. We selected two articles to refer you to, and suggest you read all of both. While the first one, Is Over-Watering Harmful? is from the UK, we felt it still applied to your situation.  From The second article, from Green Thumb Articles, Garden Irrigation, we extracted the following paragraph:


"Irrigation alters two parameters in the soil. First, obviously and self-evidently, water is added to it; less obvious, but no less critical, is that the percentage of oxygen present in the soil is subsequently reduced. As the plants are dependent on both a ready supply of oxygen in the root zone, together with adequate moisture, it follows that correct irrigation practice, always takes account of both these factors. Over-watering therefore, could more accurately be termed, 'lacking in air'."

The early leaf browning and drop of your shrubs can certainly be largely attributed to the drought, but the sudden infusion of water, essentially closing out the oxygen also needed by the roots, certainly didn't help. We don't think you killed the cherry laurels, but if they are in clay soil without any compost or other amendments to make the drainage more efficient, watering the plants becomes even more critical.

We recommend you consider how good the drainage is by filling a shallow depression with water and observing how quickly it disappears. If it takes more than a half hour to drain away, you do have a drainage problem. While it's a little late now to add amendments to the soil to improve drainage, you can certainly modify your watering practices. Any new plant, particularly a woody plant, is very susceptible to transplant shock. Transplant shock is almost inevitable if you plant in blazing hot weather. In particular, woody plants should be planted in Texas in the Winter, when they are semi-dormant. Rather than failing to water and then overwatering, it would be far better to stick a hose down in the soil near the trunk and let it dribble slowly for about a half hour, twice a week; this should continue for several months unless ample rains have returned.

Finally, have you lost your plants? Try the thumbnail test, beginning fairly high on the branches, scratch off a very thin sliver of the skin. If there is a thin layer of green beneath, that tree is still alive. If you do not encounter green up high, keep moving down the plant to the root area. Plants in a stressful situation often protect themselves by dropping leaves to reduce the load on the roots and vascular system. Those dead leaves will not turn green again, but when it is leafing out time again, probably in the Spring, you should see the plant begin to recover.

Summing up: even in water rationing, you can hand water. A couple of low-level waterings twice a week can save a great deal in resources in the long run.

 

 

From the Image Gallery


Cherry laurel
Prunus caroliniana

Cherry laurel
Prunus caroliniana

Cherry laurel
Prunus caroliniana

More Shrubs Questions

Growing Buttonbush in California
May 24, 2015 - For the Buttonbush, how do you keep it consistently moist?
view the full question and answer

Exotic plant/shrubs for Marietta, GA.
April 01, 2010 - Hi. I live in Marietta GA. and i am looking to add some curb appeal to my front lawn (around the border of the house). I would like evergreen plants and shrubs. I love the tropical/exotic look. do you...
view the full question and answer

Foundation plants unlikely to provide good shade for rattlesnakes in TX
August 28, 2011 - I would like to plant native grass around my new home in the country near Mason, TX. My concerns are the rattlesnakes that are common here, and if they could "hide" in the native grasses since they ...
view the full question and answer

Native plants for morning sun in Pembroke MA
October 07, 2009 - Could you please suggest native groundcover,plants/shrubs/grasses for eastern facing slope which gets morning sun? It is my front yard which slopes down toward driveway so it would be a major focal po...
view the full question and answer

Failure to thrive of Actaea simplex in Washington State
September 07, 2008 - I have a Actaea simplex 'Hillside Black Beauty' that I planted in mid August 2007 in a partial, almost full shade spot. This year it came back , but the foliage is brown with dark and light green a...
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP | STAFF
© 2015 Lady Bird Johnson Wildflower Center