It is important that you know what weeds you are dealing with, how they grow, and which Herbicides will work on what plants.
Life Cycles of Weeds
Annual- These grow from seeds and die in less than a year. They will return year after year.
Biennial- Weeds that have a complete life cycle in 2 years.
Perennials- These weeds have a life cycle of 2 or more years. They are the most difficult to control due to the extensive root system.
Herbicides and how they work
Pre-emergent’s- Herbicide used to prevent or retard the growth of germinating weed seeds. They are used to prevent further weeds from growing only. They will NOT work on weeds actively growing.
Post-emergent - Herbicide used to control weeds that are actively growing. They will NOT prevent the growth of future weeds.