I recently picked up some spent mushroom substrate (straw) as it was offered for free. Now I’m wondering how best to use it? Do I compost it? My only issue is that I don’t have the greens to match, and my little compost pile just recieved a load of browns recently. Do I mulch with it? I currently have a chip mulch in my garden but I’m open to layering the straw on top. Would an impending Canadian winter affect it negatively, or should I keep it bagged up until spring? Alternatively we have a berry patch that could always use mulch. It looks like I can grab another batch of this size if it’s worth doing. This is new for me, so any advice would be appreciated. TIA