How do I keep weeds out of my perrenial garden without digging up my flowers to put a weed mat under them?

I don't want to use a weed mat becuase then I would have to dig up all of my already planted flowers to get the mat under them. I want somthing to keep out weeds and make my garden look more tidy. Prefferably somthing that will stop the weeds from growing thier deep roots like they do in my area.

How do I keep weeds out of my perrenial garden without digging up my flowers to put a weed mat under them?
There's a product called "Preen" that you can incorporate into the soil that prevents weeds from growing. It's safe to use around perrenials and annuals (the desirable plants in your garden). People I know swear by the stuff and put a good dose of it on in the spring and then again do a maintenance sprinkling of it in mid-summer. It's a granual product.
Reply:Whichever method you decide to use you MUST remove the weeds, roots and all, before you start or you'll have the same problem again. Preen is my favorite.
Reply:If you weed the area out very well and use a ground cover such as bark a couple of inches thick it will keep the weeds manageable. If you pick out the weeds as they are just starting it's easy to keep up. The bark keeps the light from germinating the weed seeds.
Reply:You could use a thick layer of mulch, it will help retain moisture in the soil, keeps the soil/roots cool in summer. Some weeds will push through, but not as many, and they're usually easier to pull out too as the root in the mulch and not the soil.