What To Do When You Miss A Pre-Emergent Application

By Andy Keeton on March 18, 2021 in Blog2 Comments

What To Do When You Miss A Pre-Emergent Application graphic

Pre-emergent herbicides are an important tool in any lawn care program, but correctly timing the application can be tricky. Applying a pre-emergent too early can allow time for weeds to germinate and grow after the residual barrier has dissipated. Applying too late counteracts the purpose of using a pre-emergent in the first place by missing the optimal application window.

Time Pre-Emergent Applications Right

To know whether or not to apply pre-emergent herbicide now, it’s important to know how weeds are classified. Here are two of the main classifications and when to address them.

1. Summer Annuals Examples:

  • Crabgrass
  • Sandbur
  • Spurge
  • Dandelion
  • Doveweed

Life cycle: One year with germination in the spring. They flower and produce seed, then die in fall.

Pre-emergent timing: Early spring or late winter for southern and coastal U.S.

2. Winter Annuals Examples:

  • Annual Bluegrass (Poa Annua)
  • Henbit
  • Chickweed
  • Wild Onion
  • Mustards

Life cycle: One year with germination in the fall. They flower and produce seed quickly, then die in spring.

Pre-emergent timing: Late summer/early fall. General rule of thumb is by September 15.

Remember that weed control is a continuous process. A healthy lawn will be more weed resistant, so be sure to practice good turf care. Timing your pre-emergent applications correctly will make them as effective as possible, so be prepared.

Missed Application Window

The ideal time to apply pre-emergent herbicides is when soil temperatures consistently reach 55 degrees at a depth of 4 inches. When the application is made too late, the product doesn’t have enough time to work before seeds germinate. So, what should you do if you miss an application window? Try alternative weed control methods such as landscape fabrics, mulch or specialty post-emergent herbicides.

Landscape fabrics control weeds while still allowing water and air through and conserve soil moisture. Mulch suppresses weed growth through conserving soil moisture and allowing plants to grow stronger, overcoming weeds and by blocking vital sunlight from sprouting weeds. For weed control in turf, specialty post-emergent herbicides like Scepter T&O and Certainty and directed applications of Ranger Pro will clear up any problem weeds.

Alternative weed control options are a great way to manage weeds if you’ve missed a pre-emergent application window. For more tips and product suggestions, contact your local Ewing store.


What To Do When You Miss A Pre-Emergent Application graphic
Andy Keeton
Andy Keeton is National Turf Products Manager for Ewing Irrigation & Landscape Supply.

2 Responses to What To Do When You Miss A Pre-Emergent Application

  1. Greg Grodhaus May 4, 2021 at 9:56 am #

    I am a 20+ year Ewing customer. I appreciate & utilize almost exclusively your Ewing products. In this article/blog you address post-emergent herbicides & landscape fabric to control weeds if the pre-emergent window was missed. I am in the NM arid, south central high plains mountain region near Ruidoso. Think high-desert type landscape. Little if any natural turf. Most homes/commercial utilize almost exclusively hard-scape rather than natural turf. Even with landscape fabric applied (a necessity), “weeds throughout the yard in the rocks, beds, etc. are awful. In your article/blog you did not mention what Ewing post-emergent applications are recommended. My local Ewing store has recommended RangerPro – and they carry 5-gallon bottle cases. I recently purchased several cases. We’re not talking about just a periodic weed popping-up in flagstone walkways. We’re talking about 1000’s of square feet of hard-scape (stone covered) that is seriously infested with weeds – both grassy (mostly) & broadleaf (enough to irritate you). So, the issue is not simple spot application, rather, large broad areas to spray. What Ewing products do you recommend. HELP! Thanks.

    • Robyn Hazen May 4, 2021 at 5:07 pm #

      Hi Greg – In this situation, it is critical to use a non-staining, long-lasting pre-emergent herbicide in conjunction with a non-selective herbicide. Andy Keeton, the author of this article, recommends Ranger Pro plus SureGuard or Cheetah Pro plus SureGuard. Ranger Pro with SureGuard is more economical. In your area, you could get a true eight months pre-emergent control, which would save time and labor. Let us know if there are any further questions – we’re happy to help.

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