Rented an electric powered Makita HR3851
rotary hammer with a 3" wide chisel bit to break up some "hard as concrete"
Caliche soil while digging the holes for some Bougainvillea shrubs in 2.5 gallon nursery pots. The local Ace Hardware rental place charged $22 for 4 hours ($100 deposit). Sure made the task much easier
This is one strategy for disposing of the excavated Caliche soil. If you have one of those garbage containers that the sanitation truck picks up with a hydraulic arm, position it at the curb. That way you only have to move buckets of excavated soil once . . from the hole to the garbage container.
To get the most use out of the equipment rental period, also plan on removing/relocating other shrubs or small trees during that time.