Kill Weeds in Lawn: Most Effective with Herbicides

The best way to kill weeds in lawn is with herbicides. Herbicides are chemicals used to control unwanted plants. Herbicides can be broken down into two categories: Preemergents and Postemergents.

I. PreEmergent Herbicides

Any herbicide applied BEFORE the weed appears is called a preemergent. This application stops the weed seed before it germinates. Even if the weed plants are gone, the seed that was dropped is still waiting to germinate the next season.

Apply preemergent (usually granular) 10 to 14 days before the weed seeds are due to germinate. Your local garden center will know precisely when to apply preemergent herbicides in your area.

Important Notes:

  1. Do NOT plant any new grass seed for another 6-8 weeks. The preemergent will stop grass seeds from germinating as well.
  2. Do NOT aerate or thatch your lawn after this application. The chemical works by creating a thin film over the ground, which covers seedlings. Aerating or thatching will break this thin film, negating the application.

Since preemergents have no effect on already existing weeds, it is important to have postemergents on hand.

II. Post Emergent Herbicides

Any herbicide is applied AFTER the weed appears is called a postemergent. Some herbicides kill every plant they contact, while others kill only certain plants.

  1. Nonselective Herbicides - These herbicides will kill any plant it comes into contact with. They are used when no plants are wanted in an area. For example, nonselective herbicides could be used for spraying patios, walkways, and curbs. Care must be taken when spraying beds so it does not to touch anything else.
  2. Selective Herbicides - These herbicides kill certain plants with little or no injury to other plants. Usually selective types will kill either broadleaved plants or grassy plants. These are useful for lawns and golf courses. Some very selective herbicides may kill only certain plants; for example crabgrass killers on lawns.

If you get tired of battling weeds or don’t want to be exposed to pesticides, have a local lawn treatment company do it. I like how you can sign up online for a free estimate.

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