How much soil for a half whiskey barrel planter?

Half barrels are one of the biggest planters most people fill. Genuine oak barrels and plastic look-alikes vary by several inches, so measure across the inside of the top and bottom and the depth, and put your own numbers into the calculator.

What to know about filling a half whiskey barrel

Put it where it will live before you fill it. More than four cubic feet of mix is manageable dry, but once watered it is far too heavy to shift by hand. If it might need to move, set it on a heavy-duty plant caddy first.

Oak barrels sold as planters often come without drainage holes. Drill several near the bottom before filling; University of Maryland Extension notes that every container needs them, and a barrel that holds water will rot its plants and, eventually, its staves.

You can save mix. Many gardeners set a layer of upturned nursery pots or coarse bark in the bottom few inches. Keep at least a foot of real potting mix above it: Maryland suggests 12–16 in of depth for large vegetables, and shrubs or small trees want every inch. The false-bottom version is worked out in the questions below.

Three 2 cu ft bags leave about a cubic foot and a half over, enough to top up the barrel after the first month of settling. For scale, a half barrel holds roughly a quarter of what a 4×4 raised bed takes. Smaller containers: How much potting soil for a 5 gallon bucket or grow bag and How much potting soil for a 12 inch pot.