Apply pre-emergence herbicides, to control annual grass weeds, two to three months prior to weed seed germination in the spring. Apply post-emergence herbicides, to kill actively growing weeds, anytime during the growing season when the air temperature is 60 to 80 degrees F.
About this Author
Jennifer Loucks has over 10 years of experience as a former technical writer for a software development company in Wisconsin. Her writing experience includes creating software documentation and help documents for clients and staff along with training curriculum. Loucks holds a Bachelor of Science major from the University of Wisconsin - River Falls specializing in animal science and business.