There are several types of weed barriers, both organic and inorganic, and there are different advantages and disadvantages to each. Learning about each type of weed barrier and what it has to offer makes it easier to decide which one is best for your garden or yard.
Landscape plastic or fabrics are available at home hardware stores and typically come with different thicknesses. They are waterproof, which means you need to cut holes in them to allow the plants to get water and to breathe. This can also make it difficult for plants to survive if the plants are not hardy enough. Typically, you cover the fabric with 1 to 4 inches of soil or mulch to further prevent weeds.
Also available at home hardware stores, Landscape fabric weed barriers are breathable which is a benefit over the plastic type. This means that the fabric will allow water and air to go through to the plants; however, it blocks the sun from getting down into the soil and prevents the weeds from growing. You still cover the fabric with 1 to 4 inches of soil or mulch to further prevent weeds.
Newspaper/Paper Bag Barriers
Newspaper or paper bags make an excellent weed barrier. After pulling all weeds from the garden or plant area, lay down eight to nine layers of newspaper or three to four paper bags and then cover with soil or mulch. You'll get the same effect as the fabric but without the permanently damaging effects as the fabric or plastic. The newspaper allows the plants to breathe just as soil would, yet weeds cannot break through the barrier and get above to the top. Eventually though the newspaper will decompose which is both good (biodegradable) and bad, because it will one day need replacing.
Mulch in itself is a weed barrier. It helps to cover the soil, not only keeping water and nutrients in for the plants, but also keeping weeds below. While it is the most ineffective method of controlling weeds, because a few will pop up in between the mulch here and there, it is the cheapest and simplest method because nothing else is needed or used. There are also several types of mulch, including wood chips, bark, rocks, pebbles, gravel, pine needles, hay, leaves, grass, rubber, and even some more innovative materials less common are being used making the list nearly endless.