Here is what our expert said, "Round Up Quick Pro would be a good choice to get rid of existing weeds right away . Next I would probably go with Bonide Total Vegetation control as it is a soil sterilent and will control future growth for up to 1 year (applicator should be careful not to apply around desirable plants)."
Quick Pro:
http://www.domyownpestcontrol.com/roundup-quikpro-15-oz-packs-p-1125.html
Bonide total Veg Control:
http://www.domyownpestcontrol.com/bonide-total-vegetation-killer-p-1705.html