Newspaper under mulch.
And sometimes the weeds win, any way.
Horse nettle will scoot along under the newspaper until it finds a way up, but when I pull it, I get a lot of root.
Johnson Grass is impossible. Pull, wait. (Repeat for infinity)
Wiregrass. Over-the-top works if you really follow the directions and never let it move back in.
Morning glories will come up through newspaper.

Chickweed should be an accepted spring companion plant as should henbane; both will be killed by late spring heat. Both have already left enough seeds to cover Rhode Island.

I cannot defeat the weeds; I can only keep them at bay.

Pull trees before they are two years old. Likewise Privet hedge seedlings.
Poison Ivy is evil. Poke weed probably is alive and well on Mars.

Mulch, lots of mulch.

Constant hoeing. I'm continuely scratching the surface of the beds with a 3 pronged weeder to keep tiny weed seedlings from getting established. If left alone for a week you can see a green carpet of tiny weeds forming on the surface. By constantly scratching the surface, I prevent them from getting established and they eventually dry up. In the process though weed seeds are being worked to the surface for another round of weeds.
Newspapers under mulch gives me the best control.
Sprinkling granuals containing Treflan on newly weeded beds helps keep seeds from germinating. but won't do anything to weeds already growing.

I use enough mulch that reseeding annuals and perenniels don't even have a chance when I'd like them to come back. Having a lumber mill in the area makes that a cheap and easy option here. Works for me..and whatever survives the heavy mulch meets the "terminator".

Preen works for me. Maybe for one season bring in the big dogs..and then once under control you can back off.

You can use Ortho's Grass-b-gone around the roses safely. it kills crabgrass which is my biggest problem.

Begin with well-dug beds (the entire bed, not just the planting hole), then pile on 3 inches of mulch, and finally pull weeds (or use hoe)on a weekly basis. There won't be many weeds at all if that schedule is maintained, and with the mulch, weeds pull out very easily.

Kate

If you have invasive grass, there is Grass-B-Gone that you can spray them within the roses without harm.
Tracy

I use weed matting when making the beds then apply 4" or so of good dense mulch. That seems to work for me the best. However, no matter what you do, you are going to get weeds and stray grass in the beds that nothing but good old fashioned weeding will get rid of. As stated earlier, weeds and grass growing in mulch are generally very easy to pull out compared to pulling them up in the dirt of the yard.
I put in a new bed for 20 plants this past spring and it isn't mulched yet until the rose bushes are a bit bigger which is really just about now. Anyway it takes me as long to weed this bed as it does four others put together!!
John