What you need to know about Landscape Fabrics.
How does one go about selecting a landscape fabric? This is a question that has confounded anyone who has found themselves needing a good solution to weed control. About the only method available currently, is through the comparison of fabric specifications published by each manufacturer. The problem with this method is that most fabric specifications pertain to construction applications rather than landscape. Consequently, most of us become boggled down comparing specifications that have little meaning for our intended purposes. We have tried to narrow these specifications down to those that are most important to landscape applications. In an effort to give a basis of comparison to the products we have listed, we have added the Colorado Department of Transportation specifications to our product comparison sheet.
We feel the selection of a landscape fabric should be based on three areas of consideration.
They are as follows:
- The fabric should be strong enough to withstand the most vigorous stresses of application, but no more. Any added strength is offset with a reduction in water and air flow, and an unnecessary increase in the price of the product.
- The fabric should have an even, and consistent distribution of fibers, and a small enough opening size to keep weedy grasses from coming up through the fabric. Contrary to popular belief, weeds and grasses do not force their way through an obstacle, but rather grow to the light that comes through the smallest of openings or breaks that may exist. Weed seeds will also germinate in small accumulations of soil on top of a fabric, and send tiny root hairs through the smallest of openings to seek water and nutrients from the soil. This problem is largely avoided with the use of spunbonded fabrics, due to their almost microscopic opening size.
- Finally the fabric must be porous enough to allow water and air to pass freely to the soil. We feel this is one of, if not the most important characteristic of a superior landscape fabric. If a fabric does not "breathe properly" plants do not get enough oxygen, and soils become sour and sterile. This was the case when plastic sheeting was being used as a weed preventative. Another disadvantage of pour permeability is the problem of runoff. When a fabric does not accept water freely it tends to wash off the fabric taking any mulch covering, rock or bark, with it. This is a common problem people have mistakenly blamed on the texture of the fabric surface.