Fill planter to within 1" or less of the top of the rim with good quality topsoil.
Crown the topsoil in the center of the planter.Do not use potting soils with vermiculite or peat.
The vermiculite will wash away in heavy rains and the peat (in high percentages) holds too much water in the winter freeze-thaw cycles.
All planters are built with drain holes. This is important for both the health of the plant material and the health of the planter itself during winter months.
The drain hole can be covered on the bottom of the vessel with stones or screen mesh.
The maximum stone depth is 1". Keep the stones away from the exterior wall of the planter.