I've used it once and that was the same problem I came up with. The quackgrass just weaves itself into the fabric! I am so overrun with it here, I think it is going to take drastic measures....
Steve, I'm not going to get involved in the current discussion. You've got Marshall and others to handle your details. But there are a couple of things said in this thread I'd like to address from my experience.
Obviously there are different quality and kinds of landscape cloth. My experience with the woven kind that I've used is not with weeds growing through it but with Bermuda grass growing through it. The Bermuda grass sends out runners that run all under that landscape cloth. It does the same if I use newspapers or cardboard covered with mulch too but the Bermuda does not send shoots up through them. Those runners can run for several feet. Every joint is a place roots can form and shoots can come up. I have not experienced "weeds" growing through it, just that Bermuda grass.
With the landscape cloth I use being woven, roots will get up in the weave and maybe run 6" to 10" embedded in that landscape cloth, then send a shoot up through it to grow. Those are a pain to pull out. Those roots are like they are woven into the fabric. Here my only problem with this is the Bermuda grass but from what Journey said, it sounds like quackgrass is similar.
The other thing is about things sprouting in the mulch. I use wood chips on top of landscape cloth in my "ornamental" areas. These are just wood chips I get from a nearby city that chips the branches that people drop off or their street crews clean from the roadside. You might find oak, cedar, or some other good stuff in there but a lot of it is from what I call trash trees. Also, very little of it is heartwood. It's mainly new growth that rots, composts, decomposed (whatever you want to call it) very quickly. I have to remove and replace it every year or it rots and provides a good medium for seeds to sprout and grow. Bermuda grass runners also run in here, root and send up stems and leaves. These old partly rotted wood chips is usually what I mulch my tomatoes with, spreading them over two to four layers of newspaper.
Most of the dirt falls out of them during handling. When I replace the wood chips is also when I pull up the landscape cloth to get the rotted "dirt" off of it (which I try to save and use as compost) and pull the Bermuda roots out from under it and try to remove those roots that have grown into it.
My biggest problem area is under that ground-hugging spreading juniper with sharp needles and where the Bermuda grass has grown up through the X where you planted it. That's painful and I'm not real efficient in getting all the Bermuda grass roots out of there.
At least here, I can't spread the landscaping cloth, cover it with wood chips and walk away for years. It does greatly help in keeping the weeds and even the Bermuda under control in those areas, but it requires annual maintenance.
i don't use the weed barrier for the garden or landscaping. i do use it for lining my pond plant pots to keep the stones and mud from getting loose and making the pond murky while they settle in. i just reuse my gallon or larger pots i get perennials and trees in so there are lots of big round holes that need to be blocked but still need to be able to circulate water around the plants' roots.
I can't quite remember when he put it down. I remember passing him tomato plants over the fence not too many years ago and he did not have framed beds. Ken really did a careful job. The fabric is tacked to the inside of the boards with 1 by 2's. At least, I think they were 1 by 2's. Everything has rotted in the lower couple inches of those frames, including the fabric.
Good heavens! It looks like he used potting soil in some of the beds! There's plenty of perlite & peat. The quackgrass and bindweed moved right in . . . or at first, under. See, there's the problem. The paths were not covered by anything other than the flagstones. Plenty of weeds grew there. Maybe if they'd been covered with fabric, I wouldn't have this problem but I don't know.
I do KNOW that you can't trust weeds along the perimeter of your garden not to want to invade your good soil!!! They will ! You have to do something to suppress them! If the "perimeter" is immediately beside a garden bed -- those weeds are going to invade that bed! I put a 2-foot path around all my gardens! I patrol that path not only with a rototiller but a weedwacker! And, I have now ended every sentence in this paragraph with an exclamation point!
Sometimes . . . sometimes -- I think this forum should not be called "TheEasyGarden - Gardening Forum, Easy - Fun - Fulfilling... How Gardening Should Be." It encourages people to think that they can do things like cover the bottom of a frame landscape fabric and PLUNK it down on & beside a carpet of perennial weeds!
Steve
enuf of my exclamation points but i feel that I'm doing all the weeding work in a day or 2 & continuing that should have been done over the last 5 years . . .