Strange substance on my mulch - Ask Extension
I recently purchased a large quantity of bagged mulch. I haven't spread all of the mulch, but notice that there are a couple of spots on both the ope...
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Strange substance on my mulch #809967
Asked September 08, 2022, 1:18 PM EDT
I recently purchased a large quantity of bagged mulch. I haven't spread all of the mulch, but notice that there are a couple of spots on both the open mulch I've spread and on a couple of the bags I have yet to spread that there is a foreign substance that looks like some kind of foam insulation. This clearly wasn't there initially. I'm concerned about what this could possibly be; will it hurt my plants, will it hurt me or my pets? I'm attaching 3 photos. The first 2 are in my garden and #3 is the remnants of what I dusted off one of the bags. That was hard and crunchy. The stuff in the garden is still a little spongey. Do you have any idea of what this could be?
Hennepin County Minnesota
Expert Response
Good Afternoon and thank you for your question! This appears to be the rather aptly named "Dog Vomit Slime Mold." It is a common mold that appears on mulch and soil but is not harmful. If you find its appearance disagreeable, you can remove it by raking or scooping it out with a shovel however it may reappear when conditions are moist. I've included more information below for your reference. Thank you again for your question and have a wonderful weekend!
https://mastergardener.extension.wisc.edu/files/2015/12/DogVomitSlimeMold.pdf
https://extension.uga.edu/content/dam/extension-county-offices/cherokee-county/master-gardeners/newsletters/2021/2021%20AugSeptNews.pdf
https://extension.unh.edu/blog/2019/07/what-growing-my-mulch
https://hortnews.extension.iastate.edu/slime-molds
https://ask2.extension.org/kb/faq.php?id=758790
https://www.gardeningknowhow.com/ornamental/fungus-lichen/what-is-slime-mold-slime.htm
https://mastergardener.extension.wisc.edu/files/2015/12/DogVomitSlimeMold.pdf
https://extension.uga.edu/content/dam/extension-county-offices/cherokee-county/master-gardeners/newsletters/2021/2021%20AugSeptNews.pdf
https://extension.unh.edu/blog/2019/07/what-growing-my-mulch
https://hortnews.extension.iastate.edu/slime-molds
https://ask2.extension.org/kb/faq.php?id=758790
https://www.gardeningknowhow.com/ornamental/fungus-lichen/what-is-slime-mold-slime.htm
So is it anything in particular about this mulch or it could happen anytime? I've never experienced this with the bulk mulch I've purchased in the past. This mulch was bagged mulch.
And thank you for your help!!
-----Original Message-----
From: Ask Extension <<personal data hidden>>
To: Janet Weivoda <<personal data hidden>>
Sent: Fri, Sep 9, 2022 12:25 pm
Subject: Re: Strange substance on my mulch (#0079898)
From: Ask Extension <<personal data hidden>>
To: Janet Weivoda <<personal data hidden>>
Sent: Fri, Sep 9, 2022 12:25 pm
Subject: Re: Strange substance on my mulch (#0079898)
Hello-
It is likely that this mulch just happened to contain some spores for the mold and the conditions were right for it to grow. If the mulch was stored in plastic for a longer time, the condensation from the bags would make a moist environment that would encourage mold growth. It is a bit unsightly but harmless.
Happy Gardening!
It is likely that this mulch just happened to contain some spores for the mold and the conditions were right for it to grow. If the mulch was stored in plastic for a longer time, the condensation from the bags would make a moist environment that would encourage mold growth. It is a bit unsightly but harmless.
Happy Gardening!
