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?

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
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
3 ratings

Sunday - April 27, 2008

From: Leander, TX
Region: Southwest
Topic: Pests, Herbs/Forbs
Title: Problem with Eupatorium greggii
Answered by: Barbara Medford

QUESTION:

At the Garden's fall plant sale in 2006, I bought some Eupatorium greggii. It did very well last year. Recently, the entire plant looks like it is just wilting from the top down, as if it has some sort of disease. Moisture is not the problem. The Conoclinium greggii I have elsewhere does not seem to be affected. Do you have any idea if this plant is prone to a virus? Any other ideas?

ANSWER:

Eupatorium greggii is now considered a synonym for Conoclinium greggii (palmleaf thoroughwort), which explains why we couldn't find Eupatorium greggii in the Native Plant Database. Beyond that, however, we are still very puzzled as to what could be causing your plant to decline. Have you checked for red spider mites or whiteflies? Try tapping an affected leaf over a sheet of white paper-if you get little red spots, that's red spider mites. If you see what looks like flying dandruff, that is whiteflies. Honeydew excreted by whiteflies glaze both upper and lower leaf surfaces, causing the development of black sooty mold fungus. Just about every reference we checked referred to Conoclinium greggii (palmleaf thoroughwort) as almost pest and disease free, but you may have gotten caught in the "almost." The only other possibility we could think of is that this plant needs afternoon shade, and if it is in full sun all day, it will need additional water. These are very sturdy plants, and spread by rhizomes, which sometimes makes them almost a nuisance, but they are wonderful for butterflies. We would suggest that, if you feel the insects mentioned are the culprits, that you first trim out all the affected foliage, and dispose of it where the insects living on it will not be transported to other plants. Then try a weak solution of Safer insecticidal soap, sprayed on it two or three times in a week, because of the various stages of development the whitefly goes through. The main point is to prevent the spread of these insects to other plants in your garden, so you'll need to keep a watch out for that.

 

More Pests Questions

Swarming insects on non-native willow in Washington PA
September 25, 2011 - I have had a very large, beautiful pillow willow bush/tree growing next to our garage for about 8 years. Last year at the end of August, it began to attract white-faced hornets and yellow jackets by t...
view the full question and answer

Disappearance of leaves on desert willow in Tucson AZ
August 08, 2009 - We have a Lois Adams Desert Willow (Tucson, Az). The leaves will pump out and then a day or so later, all of the leaves are gone. The only bugs we've seen on it are very, very small ants. Could this ...
view the full question and answer

Eliminating muskrats from a cottage garden in Ontario
August 22, 2010 - We have perennial gardens at our cottage and for the first time this year the muskrats have come and leveled everything..shasta daisies, coneflowers, day lilies, phlox, etc. Any suggestions as to how...
view the full question and answer

Reaction to something in the garden from Dowling MI
May 25, 2012 - In late March I was working in my yard raking etc. The next morning I had three black spots between my knee and shin that were swelling and feverish. Two days later the areas became bigger and began...
view the full question and answer

Box elder beetles in Austin TX
February 02, 2012 - We have an large infestation of box elder beetles. They are crawling all over the yard and sometimes on the outside of the house. When you walk in the yard a cloud of them rises up and fills the air. ...
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.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP
© 2014 Lady Bird Johnson Wildflower Center