We report highly tunable control of holes in Ge/Si core/shell nanowires. We demonstrate the
ability to create single quantum dots of various sizes, with low hole occupation numbers and
clearly observable excited states. For the smallest dot size, we observe indications of single-
hole occupation. Moreover, we create double and triple tunnel-coupled quantum dot arrays.
In the double quantum dot configuration, we observe Pauli spin blockade. These results
open the way to perform hole spin qubit experiments in these devices.