I am looking for some ideas for potted trees. I need to give a bid for approx. 20 pots with trees and annuals installed. The client doesn't want the usual alberta spruce or yew either. I am in zone 6 and plants will be placed from full sun to almost full shade. I was thinking about sinking some 6" pots in the soil around the trees to install annuals in. If anyone knows where I can find large pots or has any suggestions for care please let me know.