Woven Fabric Weed Barriers

Considering using a weed barrier to prevent weeds from sprouting and saving yourself hours of back pain from weeding?  If so, we recommend that you use a woven fabric weed barrier (aka ground cover).  Most professional landscapers use fabric weed barriers these days.  Fabric blocks sunlight from the weed seeds hiding in the soil so they have less chance of germinating.  Its woven construction allows moisture and air to work their way to the soil and roots.  Make sure to cover the barrier with 3 to 4 in. of mulch; otherwise, weed seeds can finagle their way down to the fabric and actually sink roots through it.

The virtue of landscape fabrics is that, like black plastic, they serve as clean, durable weed barriers, but unlike black plastic, they permit air, water and nutrients to penetrate to the soil.  Also, a layer of organic mulch applied over landscape fabric will decompose more slowly than it would if allowed to come into direct contact with the soil.

Black Plastic Weed Barriers

Like stone, black plastic won't decompose; unlike stone, it's easy to clean.  Plastic may be the way to go if you have damp basement problems.  However, not only does it draw heat (like stone), but it also prevents air, water and nutrients from penetrating into the soil. These drawbacks will become important when you install plants in the area later.

When using two or more lengths of landscape fabric adjacent to each other, be sure to overlap. Overlapping sheets of landscape fabric blocks weeds so they don't poke up through the seams.  The instructions on the "Weed-X" wrapping say to use a 3-inch overlap, but we recommend being on the safe side and overlapping by at least 6 inches.

Install landscape fabric with the black, shiny side facing up.  If it's windy outside when you begin your installation weigh your fabric down with anything heavy you can find, so that it won't blow.  Roll out the fabric over the entire area you wish to cover before securing it with garden staples, just in case you might need to make any adjustments with the fabric.

Slope the soil away from your foundation 1 or 2 in. per foot, then install black plastic. Slit the plastic near the plants so water can penetrate to the roots. Shredded bark and wood chips tend to slide around or get washed off plastic, especially sloped plastic.  To counteract this, either use gravel for mulch, which will stay put, or use the big metal staples available at landscape centers to secure fabric over the plastic, then install wood chips.

Mulches

Cover WEED-X completely with a 2-inch layer of pine needles, wood chips or shredded bark to protect it from sun.  If a stone covering is used, use only a thin layer of small, smooth pebbles.  Resist the temptation to think, "If some mulch is good, more is better."  Remember, organic mulches such as bark will eventually decompose.  Therefore, if a deep layer is applied, you're just inviting weed seeds to germinate and strike down deep roots. Such roots will eventually compromise the integrity of the landscape fabric.  Weed seeds can germinate even in stone mulches.  As organic matter blows over the stones, it leaches through the spaces between the stones.  Eventually, it decomposes, and weed seeds that come into contact with it will germinate in it.  The deeper the layer of stones, the more organic matter that will get trapped within.

Once you've successfully installed a weed barrier in your planting bed whether plastic or woven and covered it with mulch, what do you do when it's time to plant a shrub or plant with all that fabric and mulch in your way? 

After laying down such an effective weed barrier, it almost seems a shame to have to puncture it, so that you can plant.  But alas, there's no other way.  However, don't get carried away when making incisions in your weed barrier for planting.  You don't need to cut a big circle out of your landscape fabric in order to accommodate the shrub.  There are two general principles to follow when making incisions in landscape fabric:

1. Keep the incisions as small as possible.

2. Make slits in the landscape fabric, rather than cutting out and removing portions of landscape fabric.

Clear the mulch away over the projected planting spot, just enough to gain access to the landscape fabric. But it's the cut that you should take note of.  Merely make an x-shaped incision in the landscape fabric.  The x-shaped incision gives you sufficient access to the soil for planting.