A round-mouth shovel is the principle tool you’ll need, ideally one with a long, straight handle. (D-handled gardening shovels are short, which means more bending down.) Start by defining the circular outline of your hole, about 12″ in diameter for a 6″-diameter deck or clothesline post: Push the shovel blade into the dirt vertically, stepping on the back edge of the shovel. Wear heavy, stiff-soled footwear to protect your feet as you push the blade about halfway into the soil. Lever the handle back, then lift out your first clod of dirt and set it to one side. Work your way around the circle, going lower as you do, using the back edge of the shovel blade to give you the vertical hole sides you need.
The glacial past of cottage country means you’ll almost certainly hit a stone or two that a shovel can’t shift, and that’s when a pry bar helps. Pry bars bring force to bear on a small tip area, letting you get under the edge of a stone and wiggle it loose. The best bar is straight, weighing 15 to 25 lbs., with a tip that looks like a blunt chisel. Pound downwards like a pile driver, lever sideways to loosen a stone, then remove it with the shovel. A clamshell post-hole digger makes it easier to remove soil as the hole depth increases, but this tool isn’t essential.
All post holes need to extend below the depth of frost penetration to remain stable—typically 3 to 4 feet. After you’ve reached this depth, use your pry bar and shovel to make the hole progressively larger as it goes down. This slight bell shape prevents expansion of freezing soil from pushing the post up and out incrementally.
1. Hold your arms parallel to the ground, tilting the shovel out so the blade is vertical. Push, don’t stomp, on the blade with your foot as you wiggle the handle—digging is hard enough on joints without the impact of pounding. As the hole gets too deep to use foot pressure on the blade, swing your arms down, letting momentum drive the shovel into the dirt.
2. Loosen the dirt by levering back on the handle, but be careful of over-stressing it. All that leverage plus heavy soil can suddenly snap the handle, even a new hardwood one. Keep your back straight and angled forward slightly when lifting shovelfuls of dirt out of the hole; step back with your dominant foot.
3. Rotate the blade to tip the soil. Drop the first loads of soil about 24″ from the hole to leave room for more. Avoid twisting your back; instead, turn your feet in the direction of your throw. As you dig deeper, lift the shovel with its tip pressed against the side of the hole to keep dirt on the blade.