Spent mushroom compost as mulch around trees?

[gbig2]

Hello all! Happy Holidays!
What do think about using spent mushroom soil as a mulch around trees? I just extended the mulch ring around my trees by removing the turf and was thinking about using it to mulch instead of wood mulch. I can get fresh mushroom soil locally, for free, direct from a mushroom house. The trees I have are:
Autumn glory maple
Thundercloud plum
Red Sunset maple
Crabapple
Autumn purple ash
A quick google search shows that these trees aren't super sensitive to PH. The mushroom soil has a PH around 6.8. Do you see any issues with using it as a mulch, maybe three inches thick under the drip line of the trees but a couple inches away from the trunk of course? I believe it will do everything a wood mulch would do, weed control, moisture retention, etc.?

Thanks

 

[ponyexpress976]

weeds will grow in it like crazy. it's great stuff as a soil conditioner though. top dress my lawn with it once a year in the fall after aerating.