Large outdoor pile,though the black woven ground cover( landscape fabric) 1, let some rain into the pile,2, help keep some heat in the pile during the winter.3 letsome air into the pile as opposed to a tarp would cut off all air flow.
The woven ground cover fabric used by market gardener's is said to let some air,water threw,and being black may help with heat in the winter.
Thank you all for comments.
