Postemergent herbicide

Postemergent herbicides kill weeds present at the time of application. Weeds must be actively growing when the herbicides are applied.

Postemergent herbicides like glyphosate (such as the brand Roundup, from Monsanto) present challenges when used in an established flower garden.

Because postemergent herbicides are primarily absorbed through the leaves, opt for liquid sprays rather than dry granular types if possible.