by Mary Salinas | Oct 22, 2019
Gardeners are always fighting the endless weeds that pop up in landscape and flower beds. When homeowners put in a new landscape bed and want to prevent future weed invasions, many think that putting down landscape fabric is a great way to keep the weeds from emerging and protect the newly planted trees, shrubs or perennials.
An example of failure of landscape fabric to control weeds less than 2 years after planting. Note the peeking through at the edges. Photo credit: Mary Salinas, UF/IFAS Extension.
Is Landscape fabric a good choice? Why or why not?
If landscape fabric is not covered up, sunlight will degrade the fabric. When mulch is placed on top of the fabric (and we all do want to cover it up – the fabric is not very attractive) the mulch breaks down into soil. Inevitably, weed seeds blow in and settle and germinate and grow on top of landscape fabric. And here you are with a weed problem. Weeds also find their way into the openings cut for desirable plants and along the edge of the fabric.
Landscape fabric is porous when put in place to allow water to pass through, but as time passes, the pores can get clogged and water penetration is restricted – rain and irrigation runs off and the plants you meant to protect are not getting the water they need.
Maybe the worst effect is that the landscape fabric creates unfavorable soil conditions. A healthy soil is key to good plant health. One thing soil needs to have is an exchange of carbon dioxide and oxygen between the soil and the atmosphere. Recent studies from Washington State University demonstrated that gas movement between the soil and the atmosphere is restricted about 1,000 times more when landscape fabric is present than when areas have only wood mulch.
So, if landscape fabric is not a good choice, what is?
Mulch made from wood, bark, fallen leaves and pine needles. See Gardening Solutions: Mulch for sustainable ideas.
For more information:
Improving Weed Control in Landscape Planting Beds
by Beth Bolles | Aug 12, 2016
Homeowners and horticulture professionals spend time to develop an attractive ornamental bed only to have weeds take over months or a few years later. One common method in the attempt to prevent weeds is to apply a landscape fabric around plants in beds and place a layer of mulch on top to dress it up. The thought is that this barrier on top of the soil will prevent a large number of weeds from emerging. The fabric physically prevents the growth of weeds form the soil below and blocks sunlight from reaching weed seeds. Available fabrics are labeled as porous to allow air and water to move through them and reach ornamental plant roots.
On paper, landscape fabric sounds like a good idea and it may work for a little while. Over time, soil particles and decomposing mulch fill up the porous spaces in the fabric which prevent air and water from reaching plant roots. Even with irrigation or routine rainfall, plant roots often do not receive the needed water and air for healthy growth. Plants may respond by trying to send roots through fabric seams which breaks down the intended weed barrier. Other plants slowly decline or may die quickly due to water stress or lack of sufficient air movement into the soil.
Fabric may initially prevent some weeds but it can also prevent air and water movement. Photo by Beth Bolles, UF Extension Escambia County
Weed seeds also find their way into the mulch that is on top of the fabric from nearby lawns and landscapes. The next thing you know, you have an entire weed crop growing in the mulch on top of your landscape fabric. Perennial weeds such as torpedograss and purple nutsedge eventually grow through fabrics.
Seeds from annuals like Chamberbitter easily get into mulch from surrounding areas and grow on top of fabrics. Photo by Beth Bolles, UF Extension Escambia County
The best place to consider fabric if you want to install it in the landscape is under mulched paths or other areas without ornamental plantings where a synthetic groundcover is needed. In order to have a healthy root environment for your ornamental bed plants, it is best to keep landscape fabric out of these areas.
