Prunus Okame "Harlequin"
 

I have just bought a Prunus Okame "Harlequin" tree. The label states "Hard
pruning is recommended after flowering for stunning summer foliage".

What do they mean by "hard pruning"? I understand this term as regards to
pruning roses but I have never pruned a young tree. I am concerned that if I
prune too hard the growth will be restricted. How much should I take off
each branch?

Your help would be appreciated.

Les