If you're building your compost bin from scratch, you don't usually need to add a bottom to it. Having composting materials sit directly on soil allows microorganisms, worms and insects — creatures that facilitate the composting process — to move from soil into compost.

Does a compost bin need a bottom?

What should I put at the bottom of the compost bin? Generally speaking it is not essential to add anything in particular to the bottom a compost bin. It is important to site your bin on open soil, but if you can't, we provide advice on where to put your bin.

What should the base of a compost bin be?

Greens are grasses, fresh leaves and weeds, and vegetable and fruit kitchen scraps. Almost everyone advises putting down a layer of coarse material — corn cobs and husks, sticks, thick fibrous stalks from vegetables or tall flowers. This layer improves aeration at the bottom of the compost pile.