Thanks for the question, Weed fabric does a great job stopping perennial weeds that come up from a root system. What it can’t do is stop weed seeds like dandelions and others from sprouting and growing on top of the weed fabric. Certainly vinegar, roundup and weeding will eliminate the weeds that you see but there is an endless supply of weed seeds that end up sprouting later. I’d suggest that you start using a corn gluten weed preventer. Corn gluten is a natural product that prevents weeds from germinating or sprouting. It becomes more effective with consecutive applications as long as you don’t disturb the surface of the soil. At Hewitt’s we sell corn gluten in a product called Espoma Lawn food and weed preventer. Here’s a link: http://www.espoma.com/p_consumer/lawn_org_weed.html It can be used on the lawn to prevent weeds but is also suggested for use in flowerbeds. Remember, repeated applications increase the effectiveness. Remember also that these weed preventers won’t kill weeds that are actively growing. You’ll still need to spray or pull them. Once you’ve gotten the area weeded though the corn gluten stops any more weeds from sprouting. There is also a weed preventer called Preen that is a chemical that works the same way but doesn’t have the cumulative that corn gluten has so it need to be applied more often. Have fun, Peter Bowden