Very good site with plans and even follow up plans as well as a chart:
Hi Susan, Kill it off or Dig it out, or get someone else to do it for you!
Hi Susan, here's one idea
Spray foliage of short buckthorn or seedlings with a herbicide. Glyphosate (one brand name is Roundup) will kill all actively growing vegetation on which it is sprayed. Triclopyr will kill broadleaf plants and will not harm grasses when applied properly.
Remember to keep children and pets off this area during the treatment