Knowing how to use a weed killer is important in getting the best results, after all, that’s the point!
- Apply your Gertens Crabgrass Preventer and Lawn Fertilizer or Fertilome Crabgrass Preventer Lawn Food in early to mid-May, depending on the weather.
- Apply your Gertens Weed & Feed or Fertilome Weed Out Lawn Fertilizer regularly from late May to June until all the weeds emerge.
If you’re using a granular or liquid weed killer, plan your application around a predicted rainfall or sprinkler application, and severe hot days or mowing schedule. Apply weed killers when weeds are actively growing which can include late summer and early fall depending on the type of weed.
Applying weed killers and preventer is essential to a healthy lawn.
Getting good contact with the weeds:
- Weed killers are a contact killer, they absorb the chemical through the leaf surface and then translocate the solution throughout the plant through the plant's metabolism.
- Granular weed killers should be applied when grass is damp and should not be watered for 48 hours after application. The dampness of the grass ensures the granular weed killer will "stick" to the leaf. Water applied too soon after application can wash off the weed killer from the surface of the weed before it can be absorbed.
- During drought conditions or if you are having trouble getting adequate control, add spreader sticker which ensures proper absorption of the weed killer. During stress periods, plants tend to be more defensive and at times the addition of spreader sticker can be beneficial.
Weed killers will not prevent future weed emergence, it does not stay in the soil unlike crabgrass preventer which will last several weeks.
Weed Killer is a four-step process:
- Don't mow the lawn for 5 days before you decide to apply weed killers. This eliminates leaf area, decreasing contact. Leave your grass uncut for 2 days after
- Plan around rainfall or sprinkler application.
- Water lawn lightly before application or apply in early morning to take advantage of dew
- Stay off your lawn for 1 day after application.
Crabgrass preventer and weed killer can be used at the same time. Apply crabgrass preventer, water in, and then apply weed killer.
Additional information from the University of Minnesota Extension, “Control options for common Minnesota lawn and landscape weeds”.
The experts at Gertens are always available to answer your questions!