Any advice from anyone on this? I live in an older house with a brick patio. Patio is original as far as I know, so we're talking 50 yr old brick and mortar. Weeds now grow up between bricks constantly. I've tried round-up, herbicide (Not Celsius, though). How can I get rid of this? Should I spray a pre-e (Prodiamine?) over the patio area? I have an herb garden in the corner of the patio (back on the far side of the picnic table) that I don't want to contaminate. How would y'all approach this? Spot treat? Solarize? I don't know...just throwing things out at this point. Pictures below.