Explore Plants

Share

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
    
 

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

Friday - November 21, 2008

From: Caledonia, MI
Region: Midwest
Topic: Pests, Trees
Title: Black coloration on Star Magnolia is probably sooty mold.
Answered by: Jimmy MIlls

QUESTION:

I have a star magnolia where 90% of the bark has turned black. It almost looks burned. The tree has decent buds set for next spring. What is causing the bark to turn black?

ANSWER:

The black coloration on your Star Magnolia is most likely due to sooty mold.  Sooty mold is a fungus that grows on a sweet substance called honey dew.  Honey dew is secreted by scale insects and aphids that feed on trees. If your Magnolia hasn't lost all of its leaves yet, you can probably find the sooty mold on the foliage as well.  You should also look for scale insects clinging to the twigs of your tree. The sooty mold fungus is non-parasitic and probably will not damage the plant, but it is unsightly. The scale insects, on the other hand, are a problem that needs some attention.

I'm including links to four web sites that will make you more knowledgeable about Magnolia scale as well as sooty mold.

Magnolia Scale: Penn State University College of Agricultural Science and the Univeresity of Wisconsin Extension Service.

Sooty mold: University of Vermont Extension Service, and the University of Hawaii Extension Service

Another source of information closer to home would be to contact your County Extension Agent

 

More Pests Questions

White spots on Hibiscus leaves
August 06, 2008 - My hibiscus trees have white spots or splotches on the leaves. What is it and what can I do to get rid of it? Also, the birds are eating my tomatoes faster than i can grow them. I've used the owl &...
view the full question and answer

Petals not developing on blackeyed susans from Nashville TN
July 05, 2011 - I have an established "patch" of black eyes susans. This year, the leaves are beautiful, the centers black..but the petals are practically non existent. They didn't seem to develop correctly. Any...
view the full question and answer

Bugs eating new growth on Mountain Laurel shrubs from Dripping Springs TX
April 02, 2013 - What is eating the new growth on my mountain laurel shrubs? One plant has red bugs and the other has black (could they be love bugs?). Is there something I can do to preserve the new growth?
view the full question and answer

Tree with brown spots on leaves containing caterpillars
July 14, 2011 - We have a new little tree we planted in our yard and I went over to admire it and on each leaf there is a brown spot in which little worms are living. They are alive and moving around in the pocket th...
view the full question and answer

Weird growth on oaks in Middleburg FL
February 05, 2011 - Dear Mr. Smarty Plants; I have this plant/fungus that grows on my trees here in northeast Florida & nobody has been able to identify it for me. It looks like a clump of pine needles growing on the ba...
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.