Diy Vegetable Garden Soil Mix . To determine how much potting mix you’ll need, figure: How to fill a raised garden bed and save on soil twelve main. My Blog En Blog in 2020 Potting soil, Garden soil mix, Potted from www.pinterest.com How to fill a raised garden bed and save on soil twelve main. 2 parts compost + 1 part peat moss + 1/2 part vermiculite + 1/2 part perlite. Sprinkle in some of the organic material.