I've planted ~50 apple trees with an 18" auger. They were all fall planted. I had almost 100% success with this method. Although my ground is so rocky, I don't have to worry about the auger making the sides of the hole "hard". An 18" auger usually results in a 30" hole!
I think mine is 12 inch auger and it works fine and can do a bit of shovel work in hole once you auger. If I didn't have a tractor I would be dead LOL Best investment I ever made except for my farm LOL
I definitely need an auger for my tractor for apple tree planting. A few more by hand this year again ..... then next year convince the boss I need another tool to work smart :rolleyes: .. think I have apple rig envy!