I’m not a huge fan of landscape fabric. I’ve already posted about my opposition to plastic in the garden, but I’m actually opposed to most “permanent” forms of weed block and here’s why. Even though they block the weeds from coming up, they also block your plants from coming up/getting bigger. I saw this in a couple of gardens earlier this year. One gardener wondered why her peony looked so “sickly.” I noticed big lumps under the landscape fabric. “It’s not sickly, it’s trying like heck to survive and come up through this fabric!” We tore the fabric to let the misshapen peonies come up and looked around the garden for other plants confined by the fabric.
Weed seeds and tree seeds will still find their way on top of the landscape fabric and their roots will go right through the holes cleverly designed for water. Then, you have a mess, because you almost always tear the fabric when you remove the treelet that has rooted itself through the fabric.
The method of weed block I prefer is good, old-fashioned cardboard. I know it doesn’t sound very glamorous, but, it works. If you plan ahead, you can get the cardboard good and wet before you plant – with a good layer of leaves underneath to enrich the soil and a little compost on top to hasten the decomp of the cardboard. (It’s easier to get the shovel through that way, too.) When you get the area planted, put some mulch on top of the cardboard. I’ve done this on a couple of occasions. Sometimes, however, I don’t prep an entire area before I start plopping things in the ground. So, I put the leaves, cardboard (and mulch) down afterward. It’s a little more difficult because you’re working around the plants but still manageable.
If you don’t have cardboard, you can use newspaper. You need to use between 6 and 10 thicknesses of newspaper for this alternative to be effective. A couple of sheets won’t be enough to keep the grass and weeds down. Wet it thoroughly. It will help make the cardboard less stiff and more receptive to the mulch and it will help keep the newspapers from flying around until you get the mulch on.