En EspaŅol
Share

Ask Mr. Smarty Plants

Mr. Smarty Plants - Changing colors on Mexican Plum trees from Bellaire TX

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

Thursday - June 20, 2013

From: Bellaire, TX
Region: Southwest
Topic: Diseases and Disorders, Pests, Trees
Title: Changing colors on Mexican Plum trees from Bellaire TX
Answered by: Barbara Medford

QUESTION:

The leaves on my Mexican Plum tree have recently started turning yellow/brown and the veins in leaves are red. Is this a watering issue or disease issue? Mites are on the leaves. This has been a rapid change over the past month. I recently sprayed for the mites and will continue to do so for the next couple of weeks.

ANSWER:

According to this USDA Plant Profile, Prunus mexicana (Mexican plum) grows naturally in Harris County, so the soil, climate and rainfall should be appropriate for it there. The problem sounds to us like chlorosis, a condition usually resulting from some imbalance in the soil.

Please read this article from the University of Illinois Extension on chlorosis. Note the comment that the presence of chlorosis is often due to high alkalinity in the soil. We could not find out if your soil in  Harris County is particularly alkaline, but we usually expect East Texas soils to be more acidic.

Among the steps we would recommend are to use some sort of iron supplement, not too much, as native plants do not ordinarily care for fertilizer. Water less, because it's possible the main problem is lack of drainage in soil where the plants are growing. Watering once a week should be adequate.  Finally, using a good quality organic mulch, spread the mulch over the root area without allowing it to touch the trunk area. This will protect the roots from heat and cold and, as the mulch decomposes, will add some material to the soil to assist in drainage.

In answer to your question on whether this is a watering issue or a disease issue, here are the growing conditions for this plant from our webpage on Prunus mexicana (Mexican plum):

"Growing Conditions

Water Use: Low
Light Requirement: Sun , Part Shade
Soil Moisture: Dry , Moist
Cold Tolerant: yes
Soil Description: Dry to moist, well-drained soils. Sandy, Sandy Loam, Medium Loam, Clay Loam, Clay, Limestone-based"

As you can see, this plant is adaptable as far as soils are concerned, but does not like wet feet. You get more rain in Harris County than we do in Central Texas and if you are also watering, the roots could be standing in water, which they definitely do not like.

Next, on the subject of mites. Please read this article from the University of Missouri Extension on Aphids, Scale and Mites on Home Garden and Landscape Plants. In particular, note that these pests often will attack plants that are already under stress; for instance, if the soil in which the tree is planted does not have good drainage. Also, pay attention to the reminder to carefully read and follow instructions on the use of pesticides. The pesticide you are spraying could very well be killing instead the natural predators of the pests on your plant- ladybugs, for instance.

 

From the Image Gallery


Mexican plum
Prunus mexicana

Mexican plum
Prunus mexicana

Mexican plum
Prunus mexicana

More Diseases and Disorders Questions

Non-blooming Tecoma stans in Fredericksburg, TX
June 30, 2008 - We have an esperanza plant purchased last year from Walmart and planted outside before winter. It flowered excellently last year. Just before winter we cut it back to about a foot. So far this summer ...
view the full question and answer

Trumpet Vine Dropping Buds
July 25, 2013 - My trumpet vine is dropping its buds before flowering. This happened last year as well. Do you know what is causing this and what I can do to prevent it?
view the full question and answer

Fungus Spots on Native Bush Honeysuckle
December 03, 2010 - My native bush honeysuckle plants that I have along my back fence have leaves that are turning yellow with spots. It appears to be a type of fungus, but not powdery mildew. Any suggestions as to what ...
view the full question and answer

Problems with non-native tomatoes from Spokane WA
August 18, 2012 - I have 2 tomato plants in 1 whiskey barrel, they are in abundance with tomatoes. My problem is when the tomatoes start to ripen, half green & half light red within 1 day the tomatoes are really soft ...
view the full question and answer

Why is my Ash drooping?
June 22, 2009 - Last spring, I bought a house in Austin, TX with a large Ash tree in the front yard. It looked fine last year, but has been looking funny since it leafed out this spring. It's as if the leaves are we...
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