A small bed that contained zinnias developed an alternaria (sp.?) infection 2...

Asked September 9, 2020, 9:47 AM EDT

A small bed that contained zinnias developed an alternaria (sp.?) infection 2 years ago. Since then, I cannot plant summer annuals in that area, without them perishing due to what I believe is lingering disease in the soil. Too late for solarization now. Are there any annual flowering plants that are disease-resistant for this area that can be planted next year? There are many daffodil bulbs under this area that have bloomed well every spring in spite of the above problem. Thanks! Martie

Mahoning County Ohio

3 Responses

Hi Martie -

If you think is alternaria, marigolds are one good option for replacement. Here is a factsheet about resistance of specific annuals and perennials to common diseases:
https://www.extension.purdue.edu/extmedia/BP/ID-414-W.pdf

Alternaria is a genus of diseases that also causes early blight on tomatoes. Thus, the management practices are the same - preventing splashing of water on leaves by putting down mulch (even newspaper under it), improving air circulation in the bed and more. Details on management of this disease is on this factsheet:
https://plantpathology.ca.uky.edu/files/ppfs-or-h-01.pdf

If you have more questions, just let us know. Also, you can call in or zoom into our clinic every Thursday morning. Details are at http://go.osu.edu/virtualclinic

Thanks for the advice and factsheet! Martie

Glad to help! Have a great fall in the garden, -E.