Hi

I would just let them settle in for this year then next year you can selective prune , so keep them well watered over the summer ... they dry out very quickly so every week check to see how dry the soil is if in doubt water ..

The advice on evergreen hedging in Hessayon's Tree and Shrub book is to cut back container grown plants by two thirds of their original height immediately they're planted,to encourage shoots at the base and end up with a dense hedge down to the ground. Do not prune them again this year. Next year, prune back lightly on four occasions between May and August, although given the plant you've chosen, doing it two or three times should be fine. It actually says to clip them over rather than prune, but the large leaves on the shrub you have chosen look awful if you leave them in halves, so you can either clip them with shears or a hedgetrimmer, and then go over and tidy up, or just do it with secateurs. If you don't want a formal hedge with a rigid shape, preferring a more relaxed growth, then you needn't be too rigorous about shaping this in the second year. Allow plenty of space for spreading sideways - Prunus need to be allowed to make a fairly deep hedge from front to back.

Its more usual to plant hedging in autumn,so as you've planted now, you will need to be attentive to watering, ensuring they do not go short right up until late autumn.

Thanks Gnarly-gnom and Bamboo answers much appreciated.

One other tip: as you prune them, make sure that the top is narrower than the bottom, other wise they may go bald at the base. That is a rule of thumb for all hedges.