After cutting or sawing through a bad guy at the base, we immediately (that means right away, not 10 minutes later), painted the stump with a Roundup solution using a small paintbrush. This is effective any time the temperature is above freezing. We chose not to spray the entire plant for fear of killing valuable native seedlings that inevitably seemed to be hiding within the alien mess. Once the plants were dead, the biggest challenge was removing the bodies.
