I put new mulch on all the beds this year. Shredded bark, not too fine but not the big chunks either. We have had a lot of rain (Wisconsin) over the last week and a half plus humidity. In the shady spots the mulch is molding. I spread it about 2 to 2-1/2" thick. I raked through it to loosen it up so more air can get in. My question is, is there anything else I should do? Once things dry up I'm sure it will be fine but until then I don't want any of the plants (Hostas mostly) to get diseased. Thanks!

The spores were already in the mulch. About the only thing I know to do is to spray it all with fungicide and then repeat the spraying in 7 days. If you decide to spray it, I would use a fungicide with mancozeb or chlorothalonil in it.

Thank you Ken. I will do that. That shouldn't be a difficult task because it is just in a fairly small section right now. We got a little more rain today so I'll be on the lookout for more spots. I appreciate the input.

"The spores were already in the mulch. About the only thing I know to do is to spray it all with fungicide and then repeat the spraying in 7 days."

DrDawg, those spores you're referencing are not something that will affect the plants. Those are perfectly normal in the decomposition of mulch and are actually beneficial. Spraying a fungicide will not only be an unnecessary expense but it will not be a preventative in protecting the plants from this type of fungus. I sure do understand your concern about putting a stop to plant fungus though, especially with all the tropicals and things you grow but this type shouldn't cause you any concern. Feel free to rest easy, you've got enough to deal with in your operation.

Petruske, I wouldn't be the least bit concerned about your hostas and this mold. As is the norm just be sure to not over-mulch as that is more detrimental than the fungus you see happening.

Shoe

Thanks Shoe. I'm sure it won't be long and things will dry up and I won't have to worry about it anyway. That's Wisconsin for ya. But I DO enjoy the seasons. Used to be four. Seems lately we just have two...winter and summer.

I have a serious mold/algae problem in part of my yard. It only affects the grass so far but it has been tough to kill and control. Thus, I am really aggressive with mold here.

Grass mold is quite a big ball game and each mold is dissimilar to the next one. Some of those grass molds feed on high nitrogen while others love low nitrogen combined with moisture, the latter probably what you have to deal with due to your humid environment (just guessing here.)

I hope you can get it under control, Ken. Many folks invest lots of time and money into their lawns and I realize this must be an eyesore and bigtime headache for you to have to deal with.

Shoe (who is just happy to have grass growing that keeps him out of the mud during the rainy season!)

I agree with Shoe -- if it ever dries up (the Mich. UP seems to be becoming a rain forest at the moment) the mold will go away, and I doubt it is anything that will affect your plants in the meantime. At the most I might pull it back from the plants a bit.

In the south I'm sure mold could be an entirely different issue!

Entities that decompose mulch (dead material) do not affect live plants. It's normal for various molds and fungi to come and go in mulch. As they decompose the mulch, the plants benefit. Mulching is a form of sheet composting.