“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.