Pittosporum hedges are quite common around here.
Probably the most common variety is Pittosporum eugenioides variagata which provides pretty light grey-green and white variegated leaves. This particular variety hails from New Zealand. The non variegated variety is a weed (and is often difficult to distinguish from the native Pittosporum)
It can grow quite large if left unpruned (up to 6m) and can be grown in US Hardiness Zones 8 – 10. Heavier frosts (<10°C/14°F) will knock it about a bit…allow the frost burnt leaves to remain on the shrub until spring; once removed, the hedge will bounce back. One nice feature about this variegated variety is that it almost never reverts to the original.
My neighbour & I have these along the property line, they makes quite a nice contrast to the bare branches/dull greens at this time of year.
This particular variety has fallen out of favour in recent years – it has been replaced with many smaller-leaved varieties (mostly varieties of Pittosporum tenufolium) which can tolerate tighter clipping.
However, varieties like Pittosporum tenufolium ‘Silver Sheen’ can drop dead without warning – not a good feature in formal hedgelines – for my money, Pittosporum eugenioides is a fair bit more reliable in cool-mild climate gardens.