The Best Time to Use Weed Killer


Knowing the life cycle of the weeds you are trying to kill helps you to determine the best time to use weed killers and the type of weed killer to use. Your local Cooperative Extension Service may help you identify the weeds in your lawn.

Choosing a Weed Killer

  • Not all weed killers kill all weeds, and some are not safe to use on certain species of turfgrass. Read the label carefully to determine whether it is selective, nonselective, contact or systemic.


  • Preemergent weed killers kill weed seedlings, so in order to be effective, they must be in place before the weed seeds germinate. One of the disadvantages of using a preemergent weed killer is the narrow window of time when the herbicide is effective. To improve your chances, make a second application in about six weeks.


  • Postemergent weed killers kill actively growing weeds. Young weed seedlings are easier to kill than older weeds, so use postemergents early in the season but after weeds emerge. Weeds are very difficult to kill once they begin producing seeds. Drought stress reduces effectiveness, so water the lawn before applying postemergent weed killers and allow time for the weed killer to begin working before mowing the lawn.

Related Searches


  • Photo Credit Weed image by Necroborg from
Promoted By Zergnet



You May Also Like

Related Searches

Check It Out

How to Make a Vertical Clay Pot Garden

Is DIY in your DNA? Become part of our maker community.
Submit Your Work!