pruning an amur maple

Is May a good time to prune an amur maple? It seems to form a canopy of leaves in the summer, so I’m concerned if I prune about 25% off the top now it may not leaf out sufficiently.…

Acer Japonicum

I live outside Ottawa (zone 5b I think) and would like to know if this particular Acer would grow in clay soil in a sunny location. Any general information would be welcome. Thank you.…