I'd like to take exception to the recent article by M.S. on using augers to make plant holes. No professional would consider using an auger for planting. Augers compact and glaze the edge of the hole as they work their way down. While this is great for post holes, it's a death sentence for the plant roots.
A far better and faster way is to use either a small backhoe or an articulated trencher that will cut a fan shaped hole. The spoil from the hole is broken up and now suitable for back fill.
Post-SHTF, a good quality fiberglass handle round point shovel is all that any realistic person would need.
As a post script, if you haven't tried "Straw Bale Gardening" , it's just a great way to grow food with minimal effort and maximum results. - Loren
JWR Replies: I have witnessed the glazing that you've mentioned in heavy clay soils. But in my experience is not a big issue in light loam soil. The "best of both worlds" approach is to use an auger to start a hole, and then finish it up by significantly widening its diameter with a shovel or clamshell post hole digger. This breaks up any areas that are compacted or glazed.
The "shovel only " approach will work, but of course it is more time consuming. And by the way, good quality digging bar is a must when digging in rocky ground.