Postemergence control of weeds in cool-season turf
Fall is go time for controlling broadleaf weeds in cool-season turf. Most weed life cycles are present and susceptible to control. Here’s some advice:
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Benefits of fall weed control
- Highly effective – weeds are translocating photosynthates to roots in preparation for winter, so herbicides translocate with the photosynthates providing complete control
- Less off-site risk – broadleaf herbicides can drift onto ornamentals, trees, gardens, etc., so waiting until many of these plants are declining with the changing season limits risk. Plus, lower temperatures minimizes volatilization and off-site movement of active ingredient
- Less turf risk – cooler temperatures and improved soil moisture in fall reduces potential turf damage from herbicides
- Cultural control still important maintaining a dense turf is critical for limiting weeds. If a site has constant problems with weeds or any other category of pest, evaluate the growing conditions for soil fertility, compaction, thatch, shade, drainage, etc., and mitigate as needed
- Application timing – the application window is wide since broadleaf herbicides can be surprisingly effective deep into the fall, even in areas that go dormant with winter. With late fall applications, little or no leaf curling may be seen with target weeds, but they usually die and disappear over winter
- Spreading weeds – fall applications are especially effective with spreading weeds like ground ivy, violets, white clover, etc., but a sequential application 4-6 weeks after the initial application may be justified in areas of high weed pressure
- Need more info? – Read and follow all label directions and contact your Envu area sales manager for assistance
Envu options for postemergence weed control in cool-season turf
Weed type and life cycle |
Example | Preferred Envu POST herbicides | Notes |
Summer annual broadleaves | Purslane, knotweed, etc |
Terradex™ Crabgrass & Broadleaf, Terradex Quick Strike |
Applications to young weeds are most effective in early summer |
Winter annual broadleaves | Henbit, deadnettle, chickweed |
Terradex Quick Strike,
Terradex Power Premix, |
Fall applications to young plants most effective |
Perennial broadleaves | Wild violets, clover, ground ivy, etc | Terradex Power Premix, | Multiple applications are likely needed, fall applications prior to dormancy are most effective |
Summer annual grasses | Crabgrass, Goosegrass |
Terradex Crabgrass & Broadleaf (crab), Acclaim® Extra (goose & crab), Acclaim Accelerate (crab) |
Applications to young weeds are most effective in early summer, combined with a PRE to extend control |
Winter annual grasses | Annual bluegrass | Prograss® | Fall applications most effective |