Hi Diane: I am glad you brought this topic up. I've moved the same plant of Allium tuberosum with me from Galveston, Texas, where it apparently did not reseed to a small town west of St. Louis, Missouri where it reseeded very vigorously to the point where it was competing vigorously with several Mentha cultivars to the northern suburbs of Chicago where it reseeds, but not as vigorously as in St. Louis. I had not thought of it before, but this is a classic example of the 'invasiness' of a plant varying from one location to another. A reason to approach a screening of invasive potential of plants with a certain amount of caution. Boyce Tankersley btankers@chicagobotanic.org