Kk from Elk Grove, Ca. writes
I'd assume that would be optimum, but will it still work if weeds are left in place?
Surflan AS is a pre-emergent herbicide. This means that it will only control weed growth before they pop up out of the ground. Pre-emergents are best applied in fall and early spring to best prevent future weed growth later in the seasons. So, yes you can apply a pre-emergent without first weeding, as it will not take care of the already grown weeds - it only will prevent more future growth from sprouting.
Answer last updated on: 12/28/2013