Does Pre-Mergent Need to Contact the Soil to Work?
I am wondering if pre-mergent need to directly contact the soil in order for it to work?
I did spread pre-mergent on some shrub beds, where are covered by landscape fabric and mulch. I did use heavy weight landscape fabric, yet some weeds still creep in. I spread pre-mergent during fall and early spring. However, now I start to wonder if it's worth to do so. The weeds seemed to still merge on anyway... Originally, I was thinking that as long as there is rain soak the pre-mergent and then the water got all the stuff and then run down to the soil. I am starting to suspect that. How silly my thinking is!!!!