Brooklyn1 used his keyboard to write :
Even with Round-Up the next spring new seeds carried by wind
and critters will germinate so be prepared to apply it every year.

Hey idiot, Glyphosate has no pre emergent effect on the soil.

In other words it *will not* prevent one weed seed from germinating.

Be prepard to apply it everytime a new weed gereminates.

HTH, clueless.