Post Hole Diggers

For a handful of posts in moderate soil, a manual clamshell or hand auger is usually adequate and far less expensive. For a larger fence run, harder or rocky soil, or commercial-scale post setting, a powered auger dramatically reduces labor time and physical fatigue, and the investment or rental cost is usually justified past a modest number of holes.

One-man augers are simpler to transport and operate solo but give a single operator less control if the bit binds on a rock or root, which can cause the auger to twist unexpectedly. Two-man augers add a second handle so both operators share and control that torque reaction, which is the safer and more practical choice in harder, rockier or root-filled soil.

Choose a bit diameter that leaves adequate clearance around the post for backfill or concrete — as a general guideline, the hole diameter should be roughly 3 times the post's width for concrete-set posts, though check your specific post manufacturer's or local code's recommendation.

Depth requirements depend on local frost-line depth (to prevent frost heave), the post height and expected load, and local building code — as a general rule, post holes are often dug to roughly one-third to one-half of the post's above-ground height, but always check your local code and the fence or structure manufacturer's spec rather than relying on a rule of thumb alone.

Powered augers can handle some rock and root content better than manual tools, but very rocky soil can still stall or bind the bit, and in extreme cases may require a rock auger bit, a jackhammer/breaker to pre-break rock, or hand digging around obstructions — assess your soil conditions before committing to a specific tool for a large job.