Rent Shop Volunteer Join

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?

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
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
Not Yet Rated

Monday - October 13, 2008

From: Clarendon Hills, IL
Region: Midwest
Topic: Diseases and Disorders, Herbs/Forbs
Title: Mildew in Phlox paniculata
Answered by: Barbara Medford

QUESTION:

I planted garden phlox (phlox paniculata) in my front landscaping and it is suffering from mildew. It is wet on that side due to a down spout and it may benefit from being split. Does anyone know of a treatment to eliminate the mold? They really do not flower well.

ANSWER:

Your native Phlox paniculata (fall phlox) is probably not in any danger from the mildew, although it does make the plants somewhat unattractive. Mildew is common in the Fall, because of cool nights and still-warm days. Too much water in a flower bed, such as from a downspout, can cause other problems in plants, like root rot. You might want to consider finding a way to channel the outflow from your downspout away from the flower bed. Since your phlox is a perennial, you might also consider dividing it and moving it to another area. The best preventions of mildew are good air circulation and sunshine. Since it isn't always possible to provide those, read this article from About.com Organic Gardening on   Preventing and Controlling Powdery Mildew. One tip we picked up from this and other sources, which surprised us, is that one of the best treatments for powdery mildew is a good spray of water on the affected plants. It should be done early in the day, so that the water will have plenty of time to dry before sundown, but it does seem to work. You could go on to try the baking soda spray solution mentioned in the article, although we have heard mixed reports on the efficacy of that method. There are fungicides available, but that is likely overkill for this problem. Rake up the fallen leaves and blooms, and keep the area clean, so mildew can't winter over.


Phlox paniculata

 

 

 

More Diseases and Disorders Questions

Dieback of river fern and maidenhair fern in the Texas summer
August 28, 2015 - My river fern and maiden hair fern are dying back. I know it is hot, but they are in shade and watered regularly. The river fern is dying back from the tips. Any fungus or bugs I should be looking ...
view the full question and answer

Control of sooty mold from aphids in Crape Myrtle
February 25, 2007 - I have a crape myrtle in my front flower bed that has a sooty black substance on the leaves and trunk. I've done research and understand this is caused by aphids. My question is how do I get the bl...
view the full question and answer

Oak leaf fall causing ivy damage
August 28, 2007 - I read the A/Q in the Austin American-Statesman Saturday, August 25, regarding the leaves falling now from the live oaks. I am experiencing the same thing, but it is the leaves of my post oaks that a...
view the full question and answer

Growth on top of Echinacea purpurea (Eastern purple coneflower)
July 03, 2012 - I grow purple coneflowers in my garden. ONE plant has something growing on the top of each cone. I would like to know what it is but I don't see how I can add a photo to this post.
view the full question and answer

Is it normal for the bark to fall off an oak tree in Austin, TX
May 02, 2013 - Is it normal for live oak bark to fall off when touched? I am afraid to get near them?
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.