I have had siberian pea bushes (part of the caragana group) and they pretty much stay put. Unlike spirea that spreads like wildfire if you let it. I have a pruned caragana tree that sends up suckers within maybe 5" of the trunk but I just cut them down and they don't seem to extend any further. I planted an apple tree about 15' away so will be interesting to see how it does. Course, I have no comparison as the apple tree is new to my garden.
