What describes postemergence herbicides in relation to grassy weeds?

Postemergence herbicides are specifically designed to control grassy weeds after they have emerged from the soil. This means that these herbicides target the weeds while they are actively growing, allowing for effective eradication of the unwanted plants at this stage.

The application of these herbicides is typically carried out when the weeds are visible and can be effectively treated, allowing for targeted management of turfgrass pests. These products work by being absorbed by the foliage of the weeds, disrupting their growth processes.

In contrast, options that suggest prevention of seed germination or application before weeds appear refer to preemergence herbicides, which function differently by creating barriers in the soil to stop seeds from germinating. Additionally, the notion that postemergence herbicides are ineffective against mature weeds does not apply generally; while some may be less effective on larger, established weeds, many are formulated to handle a range of growth stages.