Famous How Much Dirt For Raised Garden Beds References. To fill a 3x6 bed with 10 sides, you will need 15 cubic feet of blended soil. A good rule of thumb is to replace or add 15 to 20% of compost to the existing soil in a raised.
Plants with longer roots need up to 90 centimeters of soil. Experts recommend adding a 2″ thick layer of compost to the raised garden bed soil each year. To fill a 3x6 bed with 10 sides, you will need 15 cubic feet of blended soil.


