brown dust of porus from fungi growth

It is breaking down organic material to make it more accessible to your plants. It's a good deal.

The brown powder are the fungi spores (how it reproduces), that particular fungi can be good or bad, it's a crapshoot... if it reappears have it identified, albeit it's kinda too late now, whatever it is you got it, forever. This is the usual result of indescriminately bringing organic matter to ones property.

Sounds like slime mold (not a fungus). Doesn't hurt anything, just unsightly. I suppose you could just hose it off. I very doubt baking soda would do anything other than add salt to your soil as well as change its pH.

Look up "Witches Butter" pretty cool stuff.

I've never seen them growing on mulch, but if they ever did they would probably be very sparse, small, and not very noticable. Also, their spores are white to light yellowish.

Here in coastal CT the extension center gets numerous inquiries about bright yellow "dog puke" on the mulch before it turns tan and then brown and sporolating. A pretty common occurance, patches about half a sq ft.

Here in coastal CT the extension center gets numerous inquiries about bright yellow "dog puke" on the mulch before it turns tan and then brown and sporolating. A pretty common occurance, patches about half a sq ft.

------------- I was considering that one, although one source says its spore mass is black. Although spores can sometimes be a different color than their mass (especially while wafting through the air), and there are other yellow slime molds too, but I haven't studied many of them.

I have something similar in the yard. A yellowish custard kind of things (2), and they look like they are on rocks, not wood.??!