The Dingo Wombat fits the Post Hole Digger just like an auger. It is far better for your plant to use a Wombat rather than a standard auger.

It is designed specifically for planting trees and shrubs in broad scale conditions. Basically it’s a disc plough that circles around a center point, digging a round garden bed with deep  center. The ideal nursery for young trees, and, if you add fertilizer while digging, it stirs that in as well.

So, instead of digging a hole with an auger, use the Wombat to dig the hole with a formed up center, well mixed soil and no glazing of the sides.