Southern blight - Ask Extension
Hello, I'm pretty sure I have southern blight in my garden brought in from a contaminated load of mulch. It is mainly affecting the creeping jenny and...
Knowledgebase
Southern blight #657417
Asked June 29, 2020, 6:52 AM EDT
Hello, I'm pretty sure I have southern blight in my garden brought in from a contaminated load of mulch. It is mainly affecting the creeping jenny and the hostas so far. I have removed the diseased plants, but my concern is that I spread the mulch over a large space. I have a dense garden and it would be almost impossible to go in at this point and dig out all of the mulch and top layer of soil. Do you have any practical suggestions for how to deal with it, or for landscapers who are experienced in dealing with this sort of thing? Also how worried should I be about the woody plants in the garden-- shrubs and trees? Thank you.
Montgomery County Maryland
Expert Response
We agree that this does look like Southern Blight disease, though we cannot say if it survived in a mulch pile or was already "hiding out" in the garden but exploded this year due to suitable weather conditions. Removal of the soil and mulch from the sites of each plant infection is also recommended to lower the surviving spore counts as much as possible. Dig out several inches of soil and discard - do not compost anything. Removal of all of the mulch throughout the garden is probably not necessary, especially since Southern Blight doesn't often infect woody plants. (It can, but herbaceous infections are much more common.)
Try to keep the soil/mulch surface dry, and when needing to irrigate, do so early enough in the day that the surface has a chance to dry by nightfall. Make sure any remaining mulch is kept away from plant bases and does not touch the stems.
https://extension.umd.edu/hgic/topics/southern-blight
Miri
Try to keep the soil/mulch surface dry, and when needing to irrigate, do so early enough in the day that the surface has a chance to dry by nightfall. Make sure any remaining mulch is kept away from plant bases and does not touch the stems.
https://extension.umd.edu/hgic/topics/southern-blight
Miri
