How can I hide the view of my neighbor's garbage cans?

My lazy neighbors don't put their garbage cans behind their fence. When you look at my house, you see a nice but small front yard and their garbage cans. Fencing for my yard is not covenant approved, so I would like to plant something that will screen the garbage cans from view. I live in Colorado so I have to contend with high altitude, about 5400 feet, as well as cold winters and hot summers. The area is in the shade of several large evergreen trees that have had there lower branches removed. Looking forward to suggestions.