Keep them Weeds Away, the Mulch Mat Way Organic, Biodegradable and Sustainable
And they keep the slugs away, they hate walking, or rather slithering, over the mats hairy surface.
They will last at least a couple of years.
Just leave them there until they go back to the soil.
It will do no harm, and perhaps a little good.
They are easily cut to size to fit any awkward corners.