Digging a post hole with a shovel and a pair of clamshell diggers is one of those jobs that sounds manageable until hole four. An earth auger turns an afternoon of that into a job measured in minutes per hole, and it is the reason fence projects stop getting postponed.
This guide covers what an auger is good for, how to size the bit, and how cordless and gas models differ in practice.
The Quick Answer
Planting, bulbs, and a modest run of fence posts? A cordless auger starts instantly, weighs less, and needs no fuel mixing.
Long fence lines or heavier ground? A gas powered post hole digger keeps going as long as you keep filling the tank.
Bit size is the decision that matters most. Match it to the post or root ball, not to the machine.
What an Earth Auger Actually Does
An auger is a drill for soil. A helical bit turns and lifts material out of the hole as it cuts, producing a clean round hole of consistent diameter and depth. That consistency is what makes it worth using rather than just faster: posts sit plumb, concrete volumes are predictable, and planting depth stays even down a row.
Common jobs include:
- Fence posts, deck footings and mailbox posts
- Planting trees, shrubs and hedging along a line
- Bulb planting in quantity
- Soil sampling and drainage test holes
- Ice fishing holes, with the right bit
1. Bit Size: Start With What Goes in the Hole
The usual rule for a fence post is a hole about three times the width of the post, which gives room for concrete or compacted backfill around it. For planting, the hole should comfortably clear the root ball.
- Around 4 inches: bulbs, small plants, soil tests, and thin stakes.
- Around 6 inches: smaller fence posts and shrubs. A good general purpose size.
- Around 8 inches: standard fence posts, larger shrubs and small trees. This is the size most homeowner projects land on.
- 10 inches and up: deck footings and heavier structural posts, and where a more powerful machine starts to be necessary.
Bit length sets your maximum depth. The Wild Badger 40V brushless auger ships with an 8 inch by 31 inch bit, which covers standard fence post depth in most regions. Frost line requirements vary by state, so check local code before committing to a depth on anything structural.
2. Cordless or Gas
This is less about power on paper and more about how many holes you are digging in a row.
| Cordless 40V brushless | Gas post hole digger | |
|---|---|---|
| Starting | One touch start | Digital ignition, easy start |
| Run time | Limited by the battery, extended with a spare | Limited by the fuel tank |
| Weight | 20.7 pounds | 41.9 pounds |
| Upkeep | Charge the battery | Fuel mixing at 50 to 1, air filter, spark plug |
| Noise | Lower | Higher |
| Best for | Planting and shorter post runs | Long fence lines and heavier ground |
The Wild Badger cordless model runs a 1600W brushless motor with a rock resistant cast steel bit, and comes with a battery and charger. The gas model is a 53cc two cycle engine producing 1.9kW at 9600 RPM idling, with a 0.24 gallon tank running a 50 to 1 gasoline to oil mix. Both sit in the earth auger collection.
Weight is worth pausing on. At roughly half the weight of the gas machine, the cordless auger is far easier to handle solo, which matters because an auger is a tool you lift and reposition constantly.
3. Ground Conditions Decide More Than Specs
An auger that flies through loam can stall in clay, and no spec sheet tells you which you have.
- Loam and sandy soil: ideal. Almost any auger handles it.
- Clay: heavy and sticky, and it packs onto the flighting. Back the bit out regularly to clear it rather than forcing down.
- Rocky ground: the hardest case. A cast steel bit helps, but expect to stop and clear obstructions by hand.
- Roots: an auger is not a root cutter. Cut through anything substantial before continuing.
- Dry hard ground: watering the area the day before genuinely helps, and is the cheapest upgrade available.
Digging Safely
An auger delivers a lot of torque into the ground, and if the bit catches, that torque goes into the operator instead.
- Call to locate underground utilities before digging. This is not optional, and in the United States it is a free service.
- Keep both hands on the handles and your feet apart and planted.
- Let go of the throttle immediately if the bit binds. Do not try to muscle through a stall.
- Keep the machine upright. A bit entering at an angle is much more likely to catch.
- Wear eye protection, gloves and boots, and keep loose clothing away from the flighting.
- On heavier ground and larger bits, work with a second person where the machine is designed for it.
Technique That Makes the Job Faster
- Mark hole positions before you start rather than measuring as you go.
- Start with the bit vertical and let the auger pull itself in. Pushing down adds strain without adding speed.
- Lift the bit out every few inches to clear soil. This is the single biggest difference between a clean hole and a stalled machine.
- Keep the spoil clear of the hole so it does not fall back in.
- Clean the bit at the end of the job, especially after clay, and store it dry.
After the Holes Are Dug
Most auger jobs are one part of a bigger project. If you are clearing a line before you fence it, a pole saw handles overhanging limbs from the ground, and a tiller prepares beds once the posts are in.
The wider range sits in garden tillers and the pole saw collection, and our guide to preparing soil for planting season covers the bed preparation side.
Spare batteries and chargers for the cordless platform are in batteries, and a second pack is the simplest way to keep digging without waiting on a charge.