You would need a huge root ball if you tried and late autumn would be the time to do it. With a plant that size I would only give it a 50% chance of success with some sort of staking. If it is just the common one I would go for it, then if it does not work get one of the purple varieties and put that in instead. They are cheap plants to by from the right place. I planted a double width 75m hedge of the purple that was 1m high for less than a £100
