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Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

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Monday - September 27, 2010

From: Austin, TX
Region: Southwest
Topic: Compost and Mulch, Diseases and Disorders, Trees
Title: What to do with a sickly American elm in Austin, Texas
Answered by: Marilyn Kircus

QUESTION:

I have an American elm that is about 6 feet tall in my yard. It is has not grown quickly this year--as compared to another American Elm that I have in another spot that is about 3 feet tall and has more than doubled in size this year. Anyway it has spots on all the leaves, white spots and brown spots, maybe some black. I thought about picking the leaves off and throwing them away, but the tree would be bare. Should I do that? Should I spray is with something? If so, what?

ANSWER:

Ulmus americana (American elm) is native to the Austin area, but unfortunately, elms are notorious for being susceptible to various pests and diseases, including the deadly Dutch elm disease.

Since we are neither plant pathologists nor entomologists, we can't diagnose your tree's problem nor recommend treatment. However, County Extension offices do have information on plant diseases and bugs in their area, so we suggest you contact the Texas A&M AgriLIFE Extension Office for Travis County. Since the elm is a valuable tree, you might also contact a certified arborist who can tell you what, if any, treatment is advisable, and recommend a procedure.

Plants are more likely to get diseases if some of their needs are not being met.

Check for:

Soil compaction.

Tree getting too much or not enough water - be sure to water deeply.

Could tree be in caliche?

Tree getting enough sun?

Can you see any differences in soil, compared to the soil the other tree is growing in?

Putting compost around the tree and spraying with compost tea helps some trees rid themselves of various diseases.

Keep trees mulched starting about one foot from the trunk and going out to the drip line.  This will help retain water and keep the roots cooler on hot days.

From our Native Plant Image Gallery:


Ulmus americana


Ulmus americana


Ulmus americana


Ulmus americana

 

 

 

 

 

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