So you've got the hankering for something leafy, shade-lending, perhaps even flowering. But you don't have the yard space. There are plenty of lovely options in trees for small yards, including the common witch hazel. Bright, fragrant, fringe-like flowers appear on bare branches in late winter. This long-lived tree stands up well to extreme cold, moderate wind, even urban pollution.
Check the USDA Plant Hardiness Zone Map to see if you can grow this tree.