What is minimum application temperature for roundup grass and weed killer?
Since glyphosate (Roundup) is a post emergent (after the weed is growing) herbicide, the minimum temperature is related to the weed being controlled. The weed needs to be actively growing in order for the herbicide to be absorbed. At 35 deg. there is very little growth in most plants and thus very little herbicide absorption. Wait until a warm day, when the weed is actively growing and the effectiveness will be greatly improved. Roundup has no soil activity, so it does not work on weeds that have not already germinated and are actively growing.
