When I moved into my current home, we had an Amur maple in the back corner of the yard. I grew quickly to dislike the tree because it constantly self seeded. I spent many hours weeding out the new trees growing from the seeds. The Amur maple was definitely not a good tree to be situated in a large mulched garden bed. It did teach me a valuable lesson though; now whenever I plant a maple tree I research whether it self-seeds, the size, the zone and the location where it is going to be planted.
The Amur maple is a lovely tree planted in the correct space. It is very hardy and does great in our cold Ottawa winters. The growth on the Amur maple is approximately 15-25′ wide and tall. Usually an Amur maple is a multi-stemmed shrub but it can be pruned into tree form. The tree has beautiful green leaves and red helicopters (samaras). The fall foliage is a gorgeous crimson colour.
Picture below is of an unknown maple. (Picture taken by Cliff Wheeler).