Depends on the city. Here in Atlanta we are a "city in a forest" and for older neighborhoods with mature trees it's more common than not.

It's a very common site and greatly increases the value of the property.

It reminds me of when I was telling my Canadian friend how my pool gets a lot of leaves in it from all the trees and they said that was unfortunate. In Austin the pools get too hot to actually swim in if they aren't shaded.