Hi Brooklyn The post hole digger I have will dig to that depth in
less than 5 minutes a hole. It also digs an 8" diameter hole. Most of
the roots on plants I pulled from past seasons ever exceeded more than
about 6" so hopefully they won't become root bound. The reason I call
it an experiment is because this test will only be done on a very small
portion of my plants as I stated, 6-8 plants. My research also shows
that dry farming lends itself extremely well to clay soil which I have.
The clay holds moisture and by withholding some water, you force the
roots to go deeper and also your not washing nutrients from the soil
near as much as normal watering.

Rich