What I especially like doing is laying cardboard down before putting woodchips on. If I need to, I can cut a hole in the cardboard when planting something through it, but it's usually rotted through after the first winter, but does wonders keeping the grass down first.
I've done this several times on different 12x40 ft areas of soil, as well as just on raised beds. Newspaper also works, if you lay it on thickly, then pile on the woodchips.
I get plenty of large pieces of cardboard (sometimes 3/4" thick cardboard!) at my local recycling center. I just go and fill up my SUV when I need to cover a wide area. For a single raised bed, I usually have enough cardboard from Amazon.com boxes.
For me, it depends on the "weed," the time of year, and the state of the bed. Typically, grasses, morning glory, and anything else that I deem to be "aggressive" is pulled & tossed on the surface or paths. If it's a wet/humid time of year I will cut/tear the roots from the stem since the weed will just keep growing if I leave it intact. When it's hot/dry I don't worry about it because the sun will dry it out before it can start growing where I toss it. If they've already gone to seed, I usually pull & toss outside of the garden. Iwill also pull weeds if the seedlings or transplants are still too small to compete.
For things that are unlikely to grow through the mulch, I just cover with more wood chips. I also cover with mulch if the crop plants are already big enough that I won't mistakingly smother them with mulch. If the weed has already gotten fairly large, I may cut/break the top off and smother the roots with more mulch.
Lately, I've been trying to dry the weeds like hay or straw by laying them over the small piece of fencing I put up for beans to climb on this summer. Since I haven't been able to get any more chips delivered lately, I'm trying to utilize all my sources of biomass for mulch, and letting them dry out helps minimize the chance of them re-sprouting after I apply them as mulch.
I do the same thing Jamin does, pull them and more wood chips when I get them.
One thing I've learned about this process is procrastination is my worst enemy. When I see grasses starting to peek through, I need to stop what I'm doing and go pull them. Too many times I've said "I'll get to those later" and before I know it two weeks have gone by and the grasses are much larger and much more deeply rooted and take ten times the effort and time to remove compared to if I had just stopped what I was doing and spent 20 minutes plucking little grasses that come out so easily.
"Study books and observe nature; if they do not agree, throw away the books." ~ William A. Albrecht
Thank you everyone I guess I have some weeds to pull. I put cardboard down on smaller areas, like walk ways, and between my raised beds, but this was a large area and my son dumped piles of chips with the bobcat. I guess it's true an ounce of prevention really is worth a pound of cure. Oh well. Thanks
“We can complain because rose bushes have thorns, or rejoice because thorn bushes have roses.” — Abraham Lincoln
I definitely have a bias due to my love of equipment, but I have great results by running a sod cutter over them with 2" depth. This generally teases the roots out and leaves weeds with roots laying on the top gasping for soil... My main weeds are grasses and buttercup.
I should mention that I set up my plantings to use the 19" sod cutter width, so these are usually spaces between garden rows, or other paths like between raised beds.