The ideal soil type for raised beds is sandy loam, which is essentially soil that is loose, well-draining, and rich in organic matter. You can buy specialty bagged raised garden bed soil to fill your raised bed. You can also create your own raised garden bed soil by combining garden soil with potting soil, making sure to use more garden soil than potting mix, usually at a 5:1 ratio. Alternatively, you can try a soil blend of 50% topsoil, 30% compost, and 20% organic matter. When buying in bulk, you should try to purchase certified organic compost, as it ensures better quality.