JoAnne Skelly: Ugly black landscape fabric a source of consternation

As a horticulturist, I have a few pet peeves. One is the use of herbicide/fertilizer combinations (I will name no names). Another is evergreens pruned into green meatball shapes, because they make my heart hurt for the poor plants. Still another peeve is the ugly black landscape fabric so often placed under rocks and mulches to reduce weeds. This supposed labor-saving device eventually shreds, rips and looks disreputable.

Another horticulturist I greatly admire, Dr. Linda Chalker-Scott of Washington State University, has the same aversion to landscape fabric, or “geotextiles.” I recently read her article “The Myth of Landscape Fabric.”

Chalker-Scott points out that using fabric to reduce weeds and herbicide use sounds like a good idea and is better than using plastic. But she goes on to say, “like the perpetual dieter searching for a permanent weight-loss pill, there is no permanent weed-control fix.” Anybody who has applied weed-barrier fabrics, as well as many of us who haven’t but walk by homes where the landscaper has, realizes they decompose. Not only that, Chalker-Scott says they “can hinder landscape plant health.”

Geotextiles break down in sunlight in as little as a year. If you put organic mulch on top, such as bark, weeds start to grow in the organic material. However, if you put inorganic mulch such as pea gravel or rock on top, you have to keep all leaves and other organic material out of the rock to prevent weed colonization. After a short time, weeds simply grow on top of the fabric and you have to pull or spray anyway.

The roots of landscape plants also will grow in and on the fabric. Then, if you attempt to remove the landscape cloth, you rip up roots of desirable plants, damaging them.

For Chalker-Scott, here is the bottom line on landscape fabrics:

• Geotextiles are not effective weed-control solutions for permanent landscapes.

• Landscape fabrics used in permanent landscape installations will eventually become high maintenance in terms of appearance, weed control and landscape plant health.

• Organic mulches are preferred alternatives for permanent landscape installations, as they can be reapplied throughout the life of the landscape without damaging the existing plantings. Organic mulches also build soil health and make weeds easier to remove.

For more information, visit Dr. Chalker-Scott’s Web page at www.theinformedgardener.com.

JoAnne Skelly is the Carson City/Storey County Extension educator for the University of Nevada Cooperative Extension.