En EspaŅol
Share

Ask Mr. Smarty Plants

Mr. Smarty Plants - One wax myrtle declining in Austin

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
1 rating

Wednesday - April 20, 2011

From: Austin, TX
Region: Southwest
Topic: Diseases and Disorders
Title: One wax myrtle declining in Austin
Answered by: Barbara Medford

QUESTION:

I have 3 wax myrtles in a row; two are doing fine and one is looking "sad". It is thinning and when I checked a few branches they were dead, I pruned it and it was dead. I have had the trees for 7 years or so. By thinning I mean this one is lighter in color and has less leaves then the other two. The trees get watered by a sprinkler system twice a week. I live in west Austin if that matters.

ANSWER:

Diagnosing "sad" even if we could see it is not easy, so we will give you some clues, and perhaps you can go from there. Morella cerifera (Wax myrtle), which we frequently recommend for Central Texas, is more comfortable a little further east in Texas, as you can see from this USDA Plant Profile Map, but still does very well in the Austin area. What you need to ask yourself is what is different in the sun exposure, watering or soil between the two healthy shrubs and the sad one. Here are the Growing Conditions from our webpage on wax myrtle:

"Water Use: High
Light Requirement: Sun , Part Shade
Soil Moisture: Wet , Moist
Soil pH: Acidic (pH<6.8) , Circumneutral (pH 6.8-7.2)
CaCO3 Tolerance: Medium
Drought Tolerance: Medium
Heat Tolerant: yes
Soil Description: Slightly acidic, moist, deep sands, loams, clays.
Conditions Comments: Requires constant moisture to get established, but both drought- and flood-tolerant once established. If temperature goes below zero degrees F, will defoliate, not releafing until spring. Tolerant of saline conditions and urban confinement within pavement."

We consider "sun" to be 6 hours or more of sun a day, and "part shade" 2 to 6 hours. Is the unhealthy plant consistently getting less than 2 hours a day? Wax myrtles need a very slightly higher amount of acidity than is normally in our alkaline soils, but if the healthier ones are prospering in your soils, we can think of no reason why the third one should not. Watering trees by sprinkler system is not our favorite choice but, again, the other trees seem to be okay. We would check, since this plant calls for high water use, just how much water is actually getting to the tree in question. If you feel, for any reason, it is drier, we would suggest pushing a hose down into the soil around the roots and letting it dribble slowly until water comes to the surface and doing so twice a week for a while. Just simply because of the position of the sprinklers, that particular tree may not be getting sufficient moisture in this extreme drought situation in which we find ourselves. Do not fertilize. You never fertilize a plant under stress-the fertilizer will be trying to force more growth out of a plant struggling to survive. 

Finally, there may be a situation over which you have no control: perhaps the roots have hit a high concentration of rock, there could have been severe bark or root damage caused by some sort of digging or mowing, or below-ground pipe installations or roots trying to get through a paving or foundation. There is one more possibility in our list of problems - fusarium wilt. Please read this previous Mr. Smarty Plants answer to explore that possibility.

 

More Diseases and Disorders Questions

Problems with Cedar Elm in Austin, TX.
August 04, 2012 - Our Cedar Elm has yellowing very dry leaves and something is eating the topmost leaves leaving holes and obviously chewed off leaf segments. Could this be two different things? Aphids and bacteria or ...
view the full question and answer

Saprophytic fungus on mulch
June 22, 2007 - I just did some major landscaping in my west Austin, TX backyard. I added many native plants and mulched all of the new beds. I did this just before the heavy rains in the past two weeks. I now not...
view the full question and answer

Tip Dieback on Lonicera sempervirens
August 14, 2013 - I have a Lonicera sempervirens (coral honeysuckle) vine in Virginia which does well early in the season, but then around July, the very tips of its shoots (just the last 1-2 inches) wither, turn black...
view the full question and answer

Diagnosis of problem with Parsley hawthorn
August 06, 2007 - I have a Crataegus marshallii (Parsley hawthorn) that is about 3 years old. It leafed out this spring and flowered lightly. As the summer has progressed, though, the leaves have been dropping premat...
view the full question and answer

Failure to bloom of Salvia greggii from San Antonio
June 29, 2011 - We bought Salvia greggii at the Wildflower Center Plant Sale three years ago and planted them in a well drained area. We cut them back early in the year as recommended at Go Native U classes. ...
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