Tree for container
I have an approximately 3x5x4 wooden container with a bench surround that had a maple in it that just died. I would like to replace it with an evergreen tree that will grown to at least 10 for privacy. I have a cotoneaster and a crepe myrtle in the yard that need to move. Would either of these work? The site gets full sun. If these don't work do you have another suggestion?
Multnomah County Oregon
The trees you have could work for this site. You'd need to judge the size of the rootball for transplanting and give it a try, as there are no guarantees of success with gardening. For other plant ideas, check with area nurseries for suggestions from their inventory or special ordering options.
This OSU Extension article has plant ideas and specific cultural considerations: "How to grow a tree on your patio", http://extension.oregonstate.edu/gardening/node/1074. An internet image search for evergreen trees for containers may help you visualize the project.
Now is a good time to make any container changes if called for. (Perhaps the reason the maple died indicates problems?) Is the drainage good? Can you provide adequate, frequent watering in the summer? A tall tree will be rootbound in a container this size, so water and fertilizers will be important considerations.
Another privacy option is to build a trellis for a vine. As with the evergreen tree option, winter winds need to be considered as well.