I have the pittosporum undulatum ... the tree, which can be found all over CA. Next month I will be breaking out the chainsaw and give them a buzz cut. Once established, cut way back helps it to stay small and thick. It doesn't look too good for a couple of months, but then it fills out real nice. Some people here use hedging shears about twice a year. Let the wood dry for a couple of years and it looks real nice in the fireplace.

first decide if you want it for a hedge or privacy tree or a focal ornamental tree this important because the "victorian box" is a large tree but you can control it by trimming it properly. if you are using it as a screen or hedge tree you can trim back like wylieinthea said good luck if this is a recently plated tree you can apply some vitamin b1 to promote root growht