Native Plants
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.
Did you know you can access the Native Plant Information Network with your web-enabled smartphone?
Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.
rate this answer
Tuesday - May 26, 2009
From: Philadelphia, PA
Region: Mid-Atlantic
Topic: Diseases and Disorders
Title: Problems with Blackeyed Susans in Philadelphia
Answered by: Barbara Medford
QUESTION:
For 8 years I successfully grew Black Eyed Susans in a fairly large area in my garden. For the last two years,almost immediately upon pushing through the ground they develop black spots and then appear to be eaten away. They continue to grow but the blooms are not vivid and the leaves are ugly. I have tried a variety of bug sprays - 3 in one,and copper dust. I just recently sprayed with Bayer Advanced-Insect control (3-in 1). I plan to spray weekly. Will that work?ANSWER:
First, stop spraying pesticides. They are contaminating the soil and the air, and killing beneficial insects. Without knowing what the problem is, you can't hope to cure it with pesticides. Have you actually seen any insects? This sounds more like a soil problem, if they are showing symptoms as soon as they come up. Another strong possibility is mold. Although a number of different plants sometimes carry the common name "blackeyed susan," Rudbeckia hirta var. pulcherrima (blackeyed Susan) is native to Pennsylvania. It is a biennial, which will continue to reseed itself if it is in good conditions. It requires full sun, which we consider to be 6 hours or more a day of sun, and dry sandy soil. If conditions have changed in your garden, some other plants may be shading your flowers. You need to always clean up the debris in the garden on a regular basis, to help prevent mold or over-wintering insects from thrivng. Over-mulching, over-watering, over-shading, over-crowding all could be causing this problem.
Read this Purdue University website on Septoria Leaf Spot of Rudbeckia.
University of Florida Cooperative Extension Service Rudbeckia hirta names several diseases and insects that may be causing the problem.
You can't treat a disease without knowing what it is. Your spraying is very likely not only not helping, but may be encouraging the decline of your plants.
More Diseases and Disorders Questions
Powdery Mildew on Monterrey Oak
July 30, 2015 - Monterrey oak developing gray-white patches on some but not all leaves leading to wilting. could this be powdery mildew?
Tree not stressed. Thanks. Best treatment?
view the full question and answer
Gaura Plants Dying In PA
July 16, 2014 - I had six gaura plants. They were beautiful last year. Now I have one that is doing well and the others are dying slowly one at a time. I don't understand this. They are on a slight slope and have ...
view the full question and answer
Leaves dropping on evergreen sumac in San Antonio
January 11, 2012 - I have a large evergreen sumac in my back yard that started off as a small shrub 10 years ago. This summer the leaves turned red and now have dropped off. Is the plant dead? It sent out two smaller pl...
view the full question and answer
What about the brown dots on my Silver sage?
June 27, 2008 - During the past year, the leaves on my silver sage bushes around the perimeter of the front of my house have turned yellow in places and there are tiny brown dots on virtually all of the leaves. If I ...
view the full question and answer
Mountain laurel with fasciation
July 24, 2014 - My Texas Mountain Laurel bush has developed several "crested branches." What causes this, is it harmful & how do I get rid of them???
Thank you!
view the full question and answer
Support the Wildflower Center by Donating Online or Becoming a Member today. |