How does Gel kill the weed?

Roundup Gel - like all Roundup weed killers - is quite smart in the way it kills weeds. The Roundup is absorbed into the weed and simply stops it from growing. The weed will eventually die.  This process can take between 7 days and several weeks, depending on the climatic conditions and the type and size of the weed. Roundup only works inside the weed, and is not active in the soil or air.