How big a hole?
The "Short and Sweet" from Grandpa:
• The hole has to be at least as big as the root system that you have to plant in it.
• Not too deep. Not too shallow. Just right!
Grandpa's "long winded" answer: In the old days, before the invention of power augers and tractor pulled tree planters, Grandpa used to have to dig holes by hand. A lot of sweat equity went into orchards back then, and many orchards were not very large because of this reason. When tractors with powered augers came out, Grandpa loved the change because it took a lot of back breaking labor out when they planted orchards with hundreds of bareroot trees. He really loved the tractor-pulled tree planters when they came out in the 70s, because he claimed that they really helped him sell a lot more trees. With tree planters, orchardists started to sit on a seat and feed into the ground thousands of closely planted trees in long rows. It was the sound of money to Grandpa!
Regardless, of the number of trees you are planting, or whether they are bareroot or containerized, a hole has to appear in the ground. Experts have been arguing about how big a hole for a long time! Grandpa, being only somewhat lazy, argues for some common sense. The hole has to be at least as big as the root system! In Grandpa's opinion it doesn't have to be twice the width or twice as deep. It needs to be as big as what you are going to plant in the hole, without having to stuff roots in sideways or jump on top of the tree to make sure all the roots are covered. Not too deep, not too shallow. Quite simple! Actually this is one of Grandpa's most "short winded" answers!