En EspaŅol
Share

Ask Mr. Smarty Plants

Mr. Smarty Plants - Leaves on yaupon holly turning brown/black

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

Wednesday - July 20, 2011

From: Arlington , TX
Region: Southwest
Topic: Diseases and Disorders, Shrubs
Title: Leaves on yaupon holly turning brown/black
Answered by: Nan Hampton

QUESTION:

Arlington TX Yaupon Holly has leaves on stems closer to the bottom of the plant and moving up that are turning brown/black. Is this a disease, over/under watering? There is black gummy soil, but it has been so hot and dry. The plant is in full sun during afternoon.

ANSWER:

There are molds (e.g., sooty mold) that blacken leaves on hollies such as Ilex vomitoria (Yaupon holly) as well as other landscape plants.  The mold forms on secretions of plant sucking insects such as aphids and mealybugs.  If it is sooty mold, though, you probably can recognize it fairly easily and it will wash off.   My strong conviction, however, is that this is a result of the extreme heat and drought that Texas is undergoing.  You can visit the U. S. Drought Monitor map to see that most of Texas is in "extreme" or "exceptional" drought conditions.  I don't know how much and how you are watering the tree, but when you do water the soil needs to get a thorough soaking—the equivalent of an inch or more of rain.  (The Texas Forest Service recommends 1-4 inches of water every 10 days.  Use a rain gauge or some sort of container under the sprinkler pattern to measure it.) This will insure the water seeps deep into the soil and it will reach the plants roots there and keep them from growing toward the surface.   Also, the roots generally grow out to at least the same distance as the spread of the tree—the drip line—so watering with a soaker hose at the drip line is an efficient way to get the water to the roots.  Be aware that it takes longer to deliver 1 or 2 inches of water using the soaker rather than a sprinkler.  Mulch spread around the tree can also help to hold in the moisture.  Here is an article, Mulching Trees and Shrubs, from North Carolina State University with good tips on mulching and here is an article from our website, Helping Plants Handle Summer Heat.

Of course, overwatering can be harmful to trees, too, with many of the same symptoms of yellowing and dying leaves.  If the soil you describe as "black gummy" is always wet and gummy then you probably are overwatering.  If your soil is always damp more than 4 or 5" down (use a screwdriver or similar sharp instrument to push into the ground), then you are watering too much.   Here is a an article, Watering Trees and Shrubs, with more information from the University of Arizona College of Agriculture & Life Sciences Cooperative Extension Program.

 

More Shrubs Questions

Removing existing shrubs from Grapevine TX
September 24, 2012 - We just bought a house and we have some shrubs and hedges we want to remove. What is the best way to remove them so that they don't grow back? We have some holly hedges, a very large cedar or juniper...
view the full question and answer

What is the name of the Texas Wildflower that smells like grape koolaid?
March 28, 2014 - Can you tell me the name of the Texas wildflower that smells like grape koolaid? I live in north west Texas and every spring, the low growing purple flowers line spots along the roadside. It's a joy ...
view the full question and answer

Hearty, bushy native plants for windowboxes in Abilene, TX
October 08, 2005 - I live in Abilene, Tx and am a horrible gardener. I would love to have window boxes with some sort of hearty bushy plant. Any suggestions, I'm at a total loss...? Thanks!
view the full question and answer

Plants for southwest Louisiana courtyard
December 29, 2009 - Hi, I live in southwest Louisiana,very close to Texas. I would like to remove the grass in my townhome backyard (east sun exposure) and create a courtyard by adding pavers. However I am planning on...
view the full question and answer

Flowering tree with non-invasive roots from Palos Verde CA
June 24, 2013 - Want a flowering tree with noninvasive roots for Palos Verdes, CA.
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
© 2014 Lady Bird Johnson Wildflower Center