Multi-Use Landscape Fabric

By Jeff Gottesfeld

Would you believe an advertisement for a product that can do absolutely everything?

Just imagine the late-night infomercial:

Breathless pitchman going a mile a minute...

It’s a microwave oven . . . and a shoe polisher! It’s a tennis racquet . . . and an urban assault vehicle! It’s a citizen’s band radio . . . and an intravenous fluid delivery system! All in one simple tool the size of a potato peeler that can handle the toughest spuds from Idaho!

Ridiculous, of course. Nothing can do everything. Yet in our highly specialized industry, some products and tools are more versatile than others. Those are the ones you want to keep on hand at all times.

One of these multi-purpose products is geotextile landscape fabric. Most landscape contractors know it for its utility for weed suppression, but that is just the proverbial tip of the iceberg. Landscape fabric can also be used in hardscape applications, for winter protection of plants and shrubbery, and for mulching trees in a way that lessens the chances of a harmful insect infestation.

The better you understand the potential uses, the better you can serve your customers. All this for as little as four cents a square foot.

The most common use of landscape fabric is for weed suppression and control, while still allowing desired plant material to flourish. “Landscape fabrics have come a long way since I started working with them several decades ago,” explains Larry DeWitt, president of the DeWitt Company in Sikeston, Missouri, a leading landscape fabric manufacturer.

“The most significant improvement I’ve seen is in water dispersal. The ability of water to penetrate landscape fabrics to the soil below is key; without that, the soil will dry out. With the newest generation of laminated landscape fabric, water penetrates like never before. Not only that, but the fabrics will not leach water from the soil. The fabric blocks when it has to block, and is permeable when it needs to be permeable.”

For most of human history, there were three options for weed control: block ’em, kill ’em, or hoe ’em. Each method had and has limitations. Mulches degrade; one windy rainstorm can pile it up at the leeward end of any planting. Hoeing weeds is thankless work and highly impractical for large areas. Weed killers were—and are—potentially toxic.

While there are important modern tools in landscape weed control, like rototillers, pre-emergent herbicides, and post-emergent controls, they’re not a panacea. Weeds, after all, are weeds.

Well-installed landscape fabric makes all the difference. Installation is the key.

First, you’ll want to prepare the soil, killing and removing as many visible weeds as possible, and follow with a pre-emergent herbicide. Then, rake and flatten the soil before placing the landscape fabric as close to the ground as possible, securing it every foot or so with garden staples. (Landscape fabric is fine for undulating terrain, too. You’ll just need more garden staples). If the area being draped is too wide to cover with a single strip of fabric, overlap layers of fabric to prevent weeds from snaking between the layers.

Once the ground is prepared and the fabric installed, emerging weeds will be stopped in their tracks. A simple “X” slit in the fabric allows for planting whatever and wherever you’d like.

To maximize longevity, most manufacturers recommend putting a two-inch layer of wood chip mulch, or a light layer of pebbles, atop the fabric. This layer will block UV rays, and extend the landscape fabric’s life. You may also want to put mulch under the fabric, so that it can decompose and add to the quality of your soil.

Thus placed and installed, landscape fabric will block weeds without the use of chemicals, permit irrigation, keep the soil moist, encourage the creation of new topsoil, and look good at the same time.

Jason Palat of Palat Landscaping, Monroeville, Pennsylvania, cautions not to use fabric that’s too light. “I’ve learned the hard way,” he says, “to use heavy-duty, commercial fabric. With the light stuff, you can’t even run a wheelbarrow over it without it ripping. I want to be able to dump gravel on top without worrying. Heavier fabric is a little more expensive than lighter fabric, but it’s worth every penny.”

To be fair, some landscape contractors are less than enthusiastic about using fabrics for weed control, citing difficulties with dust clogging, and fabrics that end up buried in topsoil as top mulch degrades. Then, removing that fabric can be messy. Marion Tray of Marion Landscaping, San Rafael, California, prefers to use sheets of cardboard for mulch. “We may need to replace it every couple of years,” he says, “but I don’t like what fabric does to the soil when it’s been in place for a while.”

{::PAGEBREAK::}Weed control is one of the jobs that landscape fabric can do well. Another important use is in hardscape installation. Landscape fabric can provide an unparalleled water-permeable membrane between the earth below and the bottom-most layer of gravel above.

“We use landscape fabric a lot in hardscape,” says Chris Herbstritt, a horticulturalist with Creekside Nurseries in Knoxville, Tennessee. “It’s particularly good for all kinds of separation issues. When we need to separate three-quarter-inch gravel from number-ten gravel, we’ll put landscape fabric in between. Fabric provides a smooth base, and there’s less chance of the layers settling unevenly.”

In some situations, contractors will also install the fabric underneath the top level of pavers but above the top-most layer of sand to prevent weeds from sprouting between the paver stones. One potential drawback here is that dirt and clippings can settle on the fabric. Over time, the fabric may become blocked by debris.

Clogged fabric can impede proper drainage. This can be a real problem in rainy and cooler climes. Imagine a heavy December rainstorm followed by a vicious cold snap. If water is trapped under the pavers, and then it freezes, there’s potential for upheaval and displacement of the pavers. Knowledge of local conditions is a must for this application.

Another use for landscape fabric is in the area of plant and shrubbery protection. Draped and secured landscape fabric can protect flowering annuals, bedding plants, vegetables and the like from cold weather, predicted storms, birds, insects, and even the blistering rays of the hot summer sun. In times of extreme cold, fabric around a plant can raise the interior temperature by up to ten degrees (depending on the ounce rating of the fabric), and make an actual life-and-death difference for the plant.

Landscape fabric works so well in this environment that some manufacturers make specialty fabrics just for this purpose. Unlike conventional landscape fabric that comes in long rolls, some of these specialty fabrics are as wide as 50 or 60 inches, for easy wrapping and draping.

Herbstritt says that he’ll use specialty fabrics that vary in UV protection from 10 percent to 90 percent, depending on the amount of sunlight he wants to filter through. In cold weather, though, he moves “to plastic wrapping, to keep the plants nice and warm.”

Not only can landscape fabric protect plant life from inclement weather, but it can also help avoid insect infestation. In a 2009 experiment conducted by scientists at the University of Florida and at the United States Department of Agriculture, and published in Florida Entomologist, the investigators draped landscape fabric around the bottom of citrus trees to determine whether the fabric inhibited diaprepes root weevil infestation.

Dr. Larry Duncan, a professor at the University of Florida agricultural research facility in Lake Alfred, Florida, said that tight-woven fabric was highly effective in preventing weevil larvae from penetrating the ground to attack the tree’s roots. “You want to make sure that the fabric is wide enough around the tree,” Duncan cautions. “Those newly hatched larvae can migrate. Five or six feet out is a safe distance.”

He says that the same landscape fabric configuration can work with other insect pests that live in the branches and leaves of trees and drop their larvae. The fabric also serves as water-conserving mulch.

Landscape fabric is in the same family as the geotextiles and geomembranes manufactured to prevent soil erosion. Shipped in rolls, there’s variation in the synthetics—like polypropylene—used as the basic material for the fabric. It’s rated in several ways.

The important ounce rating tells you how much a square yard of the fabric weighs; heavier fabric weighs more. The permeability rating, in gallons-per-square-foot-per-minute, tells you how easily water can penetrate the fabric. This is important information when it comes to irrigation. Burst strength also matters—how much weight the fabric can bear before rupturing. There are also ratings for tensile strength, elongation (shape-maintaining quality), and trapezoid tear (rated in pounds).

Lastly, you’ll see a rating for how well the landscape fabric resists exposure to the sun’s ultraviolet rays that can degrade and weaken the fabric. The higher the UV exposure rating for a given period of time (e.g., 75 percent after 2,500 hours), the longer the landscape fabric will do its job, even if it is laid down and left unprotected by a layer of woodchip mulch.

Fabrics differ in width, and color is also an option. Some landscape fabrics even have factory striping, so that you can overlap them uniformly for maximum coverage efficiency.

Weed control, tree health, insect control, weather blanketing, hardscape improvement…these are just some of the ways that you can use fabric. There are others, particularly in the arena of waterscapes. (See “Know Your Options Before Installing a Pond Liner,” in this magazine’s March, 2006 issue).

When a weed control tool can also be a pest control device, and a measure against bad weather can also make for better and longer lasting hardscapes, you’ve truly got a product that is versatile. Having one product that has many uses sure makes it easier on inventory control.

Landscape fabric might not be pitched on a TV informercial, but it’ll last a whole lot longer, and won’t gather dust in a forgotten closet, either.