how thick did you put it on???

ken

Many perennial weeds will come through even quite thick mulch - you want to clear the ground of weeds before mulching and planting. After planting the mulch prevents the germination of most young, new weeds - and makes any remainders from before planting a lot easier to pull out, because mulch softens the ground by keeping it from baking in the sun.

What answer do you want?

Smartalec: Did you weed first?

Ever so helpful (not): Did you put it on thick enough?

Sure to inspire hate mail in the internet age: Now you know why landscape fabric is used.

There are certain weeds and/or certain conditions where nothing will stop them. With those, you just have to be vigilant, and keep after them.

IMO landscape fabric is best used in perrenial beds where it can be removed and replaced every fall and put down again in the spring. I have used all sorts from the eco fabrics to the plastics and they all create a weird compacted non aerated soil underneath which IS NOT good for many plants.

Plus, they still get some weeds!

Once there is decomposed mulch, broken down fallen plant debris like tree leaves or spilled soil on top of the fabric adapted weeds will grow on top of the fabric. Otherwise if there are an holes or tears in the fabric persistent perennial weeds will come through these openings from below. And those with long perennial roots will find there way out to the edges of the fabric and come up there; woody kinds in particular can sometimes grow many yards under a barrier and then appear just beyond the covered area.

I usually put down a couple layers of newspapers and then a good layer of mulch on top of that. I tried landscape fabric once many years ago, but never again for all the reason Embothrium listed. Edge your beds with a root barrier to keep out grass. Beyond that, wander out with your morning cup of coffee (or whatever time works for you) and spend about a half hour a week weeding. After the second or third year, if you have kept up with things, there won't be much left to weed, but you will need to add another layer of mulch. I don't think I spend more that a half hour a month weeding a bed that averages about 15' x 70'.

Ken i think i put on about 3 inches. But there are tons of the same weed coming thru it.

Post a picture of the weed and we can tell you if it is annual or perennial. If the former you can pull. if the latter you'll need to dig it out before mulching.

It is primarily perennial weed species that laugh at mulch as a weed barrier. If one takes the time and trouble to deal with those first-or after the fact for that matter-mulch really will hold back on new weed seed sprouting. But it can't stop dandelions, quackgrass, or other tough perennial weeds already present. Actually, that's what glyphosate is for. I do not even consider mulching a reasonable practice if the use of non-selective herbicides cannot also be part of the picture. And no, don't use "landscape fabric" as new weed seeds will simply sprout on top of the fabric as material breaks down and as dust and other materials collect. Then you will have say, a dandelion with half its taproot above the fabric, half grown through and below the fabric-the worst possible case. Junk idea.

+oM