Jonathan,

Unfortunately, there are gads of plants that share the common name of Buckthorn. I think I know what you are talking about, but never wish to prescribe a control program without knowing for sure.

Check out the Minnesota Department of Natural Resources website and determine if we are talking about the same species. If so, there is a thorough explanation of control techniques on that site. If we are describing the same species, early control is much easier and less expensive than waiting until it spreads.

Growing Deer together,

Grant