In article ,
mcdaniel wrote:

I am anticipating seeing it again next year but hope that by spraying
when it first comes up and staying after it over the summer that I will
prevent the thick runaway growth and the seeding that goes with it.

Spraying in the spring and throughout the summer will not be much more
effective at erradicating it then spraying it once at the end of the
summer to prevent it from going to seed. Spraying it once also has the
benefit of reduced ecological damage from the herbicide use, and less
cost for the herbicide.

Here is a good datasheet from the National Parks Service which a
forester from the NCDFR referred me to:

http://www.nps.gov/plants/alien/fact/mivi1.htm

Good luck.

--
Steve