En EspaŅol

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
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

Thursday - April 17, 2008

From: St Augustine, FL
Region: Southeast
Topic: Trees
Title: Treatment of black mildew on magnolia
Answered by: Barbara Medford


I think my magnolia has black mildew. How do I treat it?


We are assuming that your tree is the Magnolia grandiflora (southern magnolia), which is native to Florida. We found an excellent website on this plant from the University of Florida Extension Service. Near the end of the article is a section on Diseases, where we found this information: "Magnolias may be subject to leaf spots, blights, scabs and black mildew caused by a large number of fungi or a bacterium, but they rarely require chemical controls. Raking up and disposing infected leaves may reduce leaf spots next year."

For better on-the-spot information and suggestions on control (or the lack of need for it), go to this website from the St. John's County Extension Office. It has phone numbers and e-mail address for you to contact them. If the problem you are having is widespread, they will be aware of it and can offer you publications and advice in your environment.

Magnolia grandiflora

Magnolia grandiflora

More Trees Questions

Growth rate of Thuja occidentalis
January 31, 2011 - What is the growth rate of thuja occidentalis? I have found web sites and books claiming slow to fast.
view the full question and answer

Madrone too close to house in Oregon
February 02, 2009 - I have a small Madrone tree (8ft tall) located approximatly 15 feet from my house, with a basement. Should I remove it? ie will it damage the foundation and is the tree strong enough that it will no...
view the full question and answer

Advice on planting Korean dogwood (Cornus kousa) in Vancouver, BC
October 26, 2007 - I live in the Vancouver, BC - Pacific Northwest area and the front of our yard faces south to southwest. If I were to plant a tree other than an evergreen, would the Korean Dogwood thrive in this are...
view the full question and answer

Damaged oaks from Hurricane Ike in League City, TX
August 25, 2009 - After hurricane IKE, one of our oak trees (in front yard) was partially uprooted from the ground. We did place it back, and tie it down with supports. Further, we inserted fertilizer spikes, and give ...
view the full question and answer

Plants to grow under elm tree in Amarillo TX
May 01, 2014 - I have a large elm tree and I can't get seem to get anything to grow under it. I was wondering if there are any shade-loving groundcovers that you would recommend (have tried English Ivy, hostas, an...
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.
© 2015 Lady Bird Johnson Wildflower Center