Hello,
I have recently purchased my new home in Ottawa, Canada, which backs on to a park. The park is very green, which is wonderful, but I want to introduce some colour variation to my back garden. I purchased a Downy Serviceberry (Amelanchier arborea) and a Japanese Maple (Acer palmatum). My plan was to plant these in either corner along the north fence, with the Serviceberry in the sunnier east corner and the Japanese Maple in the shadier west corner (see attached photo - the Serviceberry is in a pot in the east corner and the Japanese Maple is intended to be put in the west corner of the lawn/patio junction). There is 4 metres between the two trees.

My question is: Is this too close for these two trees? Is there anyway to manage these trees (pruning, etc) as they grow to allow them to both exist in my back garden with minimal problems? Any other advice would be much appreciated.