Hello nanakath. If the weeds are really bad, I would go for killing them first, every time. Tipnut.com have loads of recipes for home-made weed-killers, mostly involving strong vinegar, but I have also used bleach, as well as patio cleaner or any strong weedkiller. I am merciless. I have a cheap pump-action sprayer with a long thin nozzle. I have various size plastic tubes, but taking the bottom out of such things as large or small plastic plant pots will do the job. Plonk the tube/pot over the weeds and put the nozzle right into it and drench the things with whatever you have chosen. Of course you need a spell of dry weather and not much wind, but you can leave it it covered while you move on the the next one with another shield, until you are satisfied it has settled. Then just slice the tops off every time a new one comes up. They eventually give up. After a few years!!!