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
Not Yet Rated

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. 


Rudbeckia hirta var. pulcherrima

Rudbeckia hirta var. pulcherrima

Rudbeckia hirta var. pulcherrima

Rudbeckia hirta var. pulcherrima

 

 

More Diseases and Disorders Questions

Diagnosis of problem with Parsley hawthorn
August 06, 2007 - I have a Crataegus marshallii (Parsley hawthorn) that is about 3 years old. It leafed out this spring and flowered lightly. As the summer has progressed, though, the leaves have been dropping premat...
view the full question and answer

Habiturf installation after Take-All fungus
January 24, 2012 - Are other soil remedies needed (besides those listed in your Habiturf brochure) to install Habiturf on land which had a St. Augustine lawn which was decimated by take all patch.
view the full question and answer

Diagnosis of problems with Texas ash
June 07, 2006 - Our 15 year old Texas ash has less leaf production this year. It also has a small amount of algae on the trunk, and some of the branches have small white spots on it. Also, a few of the branches close...
view the full question and answer

Drought-resistant and grub-resistant grass for Smithville TX
October 02, 2012 - I want a drought resistant grass for a sunny area that is also resistant to grubs. I have lots of grubs but want a healthy soil of good microbes. Any ideas? Zoysia, Buffalo? I noticed that Tech Turf r...
view the full question and answer

Mountain Laurel suffering from Spring freeze
May 12, 2015 - I have a 4 1/2 ft Texas Mountain Laurel shrub in current location for several years. A hard freeze this spring killed every leaf on the tree, but the stems remained green. My other smaller Mt. Laure...
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 | STAFF
© 2015 Lady Bird Johnson Wildflower Center