En Español

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?


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

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

rate this answer
1 rating

Friday - June 11, 2010

From: Huntsville, TX
Region: Southwest
Topic: Trees
Title: Pecan with brown spots on the leaves
Answered by: Nan Hampton


Southern pecan, I am a 8 foot tall and 3 year old (young)tree. My leafs have brown spots on top and hard shell mound on the bottom, this is on about 3/4 of the of the leafs, could you tell me what this is and how to fix it? Thank You.


Mr. Smarty Plants is very sorry you are ailing.  I would like to compliment you on your communication skills, however!

I consulted several sites that had information on diseases and pests of pecans.  University of Missouri Extension's Pecan Pest Management: Insects and Diseases, University of Arkansas Cooperative Extension's Home Pecan Diseases and Control, Louisiana State University's Agricultural Center's Pecan Disease Synopsis, Clemson University Cooperative Extension's Pecan Diseases, and Texas A&M University Cooperative Extension's Pecan Kernel Diseases.

Your symptoms didn't sound exactly like any of the ones listed, but here are the diseases or pests with  symptoms that most closely resembled yours: 

1) Downy spot fungus caused by Mycosphaerella caryigena

2) Pecan Phylloxera caused by the insect, Phylloxera devastratrix

3) Zonate leaf spot caused by the fungus, Cristulariella moricola

4) Brown leaf spot caused by the fungus, Cercospora fusca

Most of the descriptions of the above conditions offer recommended control measures.

You can also read a rundown of pests and diseases affecting Carya illinoinensis (pecan) from the U. S. Forest Service.

Since pecans are considered agricultural crops you might like to visit Texas AgriLife Extension "Ask an Expert" to ask them the same question.  They are likely to have a plant disease expert on hand who knows pecan tree diseases better than we do.


More Trees Questions

What about planting a Colorado Blue Spruce in Rapid City, SD?
May 13, 2009 - What would be the best tree to plant in my small front yard that would be low maintenance? I live in Rapid City, SD, and we are landscaping our front yard. We were thinking of Colorado Blue Spruce b...
view the full question and answer

Galls on live oak trees in Austin, TX
April 14, 2005 - I am a resident of a condominium complex in Austin that has numerous Live Oak trees. Can you explain what the gall type things are hanging from the trees at this time of year and all over the grounds?...
view the full question and answer

Fast-growing tree for Wilmington NC
May 22, 2010 - What kind of fast-growing tree would you plant in Wilmington, NC?
view the full question and answer

Erosion controlling plants for a shady Minnesota lakeside
August 11, 2015 - I live about 50 yards from a lake and there is a steep embankment. Recently someone decided to cut the trees off the embankment and now the dirt is eroding off the embankment as well as off my back ya...
view the full question and answer

Tree roots breaking surface in Allen, TX
March 09, 2009 - I live in Northern Texas, near Dallas. My questions concerns a tree in my front yard that now has roots that break the surface of the soil and grass. I would like to cover the roots. Should I cover...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2016 Lady Bird Johnson Wildflower Center