To mat or not to mat is a question that has been plaguing well-intentioned gardeners since the creation of the weed mat. Now it is not only to or not to, but also the question of what kind of weed mat (also known as landscape fabric or weed barrier) to use? Let’s see if we can clear up a few basic facts about what types are available and some of the pros and cons of using weed mats.
Bulbs and annuals are another consideration when applying weed mat.1
First, what are some of the best applications for weed mats? Is it beneficial in every garden? I believe that the use of a weed mat should be selective. Selective to the point that you choose it based on the type of garden and plants in that garden, the purpose of the weed mat in the bed, and the lifestyle of the gardener intending to use it. For example, an English-style perennial garden would not benefit from weed mats as the plants themselves would be prohibited from spreading, reseeding and intermingling like the style permits. However, a vegetable garden would benefit to have the weed mat covering the paths and leaving open areas for the vegetables to grow. Additionally, another application where weed mats are beneficial is under stone mulch or under gravel walkways to prevent weeds from growing.
Second, a weed mat does not last indefinitely, so if you choose to use it, it will need to be replaced at some point. This is a serious consideration when it comes to removing whatever is on top of the weed mat to replace the worn-out mat. This is also a consideration when thinking about what is either already growing in the space you want to use it, or what you want to plant in that space.
This Dewitt fabric shows both the application of stone and the staples used to hold it in place.2
Weed mat is semi-permeable and consists of a woven substance, whether that is polypropylene or coco fibers, straw or burlap. The polypropylene is the least permeable choice and can last up to 15 years depending on the weight of the fabric. Weed mat is generally secured in place with staples that are roughly 4 inches long or better. This is an additional item to remember when replacing weed mat — be sure that the staples are all removed.
DeWitt manufactures a great fabric that has a 15-year guarantee on it and it comes in a roll 8 to 15 feet wide and up to 400 feet long. The fabric can be easily cut with a utility knife. I like to cut out a circle at least 2 times the size of the pot or root ball I am planting so that the plant will have plenty of room for water to get to the roots and there is not extra fabric choking the trunk of the trees or shrubs as they grow. Some folks like to cut an “X” where the plant will go and then fold the fabric back or under; however, I have found that this is a problem later on as it is difficult to get enough water to the plants. Then, if you do succeed in watering right at the base to get proper saturation, the soil doesn’t dry out properly and the roots can rot.
Third, weed mat is not a guarantee that you will not ever have weeds. If you choose one of the thin, small rolls of weed mat that are the “homeowner special” you will see some of the pervasive weeds like dock, plantain and even dandelions push their way up through the mat. There will also be the germination of weed seeds that blow in from other yards or gardens or fields and then there are my favorites – bird weeds! These weed seeds (excreted by birds in their droppings) grow on top of the weed mat and will still need to be removed at some point.
Hopefully this will help in your quest to improve the landscape. Look at the guarantee offered on the mat you select. Also read the package to see what applications are suggested. If you are landscaping a temporary space or just want curb appeal so you can sell your house, use a product that can be easily removed. Sometimes weed mats make work easier and other times they make more work.
1. Photo courtesy of Dawn Seymour
2. Photo courtesy of Gardener’s Supply