Pros and cons of using weed barrier fabric
Q: We want to put down weed barrier in our landscape, but we just heard it is not the best idea. Can you explain why and tell us what does work?
A: The great debate! I’ll just say it up front, I am not a fan of using the black landscape fabric, with a few possible exceptions. There are several versions out there, but I don’t like any of them.
Landscape fabric is promoted as the solution for weed control. If you buy the hype, you will think weeding is history.
But hold on, like many advertised products, this one may not fulfill your dreams. I’m not sure there is any one product that will make us happy with our weed control efforts. So, let’s talk pros and cons (and unfortunately, mostly cons).
PROS: To be fair, it does have some uses.
It keeps rocks from sinking into the soil. We recommend using a leaf blower to blow weed seeds, dust and debris out of the rocks a couple times per year to keep a new layer of soil / organic matter from settling on top of the fabric.
It does prevent weeds covered by fabric from sprouting. It can reduce the need for herbicidal weed control. It works well on slopes. It can help the soil maintain moisture. It is better than using plastic.
CONS: 1. Landscape fabrics affect plant health in a negative way. Although somewhat porous, all of these products will limit air movement and water infiltration as the fabric gets clogged by soil. Thus, they reduce plant health for those plants living within this fabric.
2. Mulch, leaves and needles are all above the fabric. As you continue to add mulch and nature adds the rest, you end up with more and more soil as these decompose and the perfect environment for new weeds to emerge on top of the fabric.
3. No matter the fabric you choose, it begins to decompose but cannot be incorporated into the soil due to the make-up of the fabric. Thus, you are creating more work for later when it becomes ineffective. Plant roots will grow into it and make it even more difficult to remove.
4. You cannot plant anything new without having to cut into the fabric to plant. So that new shrub becomes a huge chore to plant and annuals are something you’ll have to leave to containers or other locations.
5. Existing soil under the fabric will not be getting the benefits of new organic matter (mulch decomposition, grass clippings, leaves, etc).
6. The cost and time to purchase and install can easily be more than reapplying mulch every year or so.
What to do? Well, mulch is great — but needs to be thick, is a lot of work and can get expensive depending on the source and the look you want in your landscape.
Best solution — paper under mulch. At least four layers of newspaper or use of painter’s paper.
Some say use cardboard. I disagree because it takes a long time to break down, especially if has been treated and is shiny.
Cover the paper with mulch, at least 4 inches. Remember to keep mulch away from the root crown of plants to prevent issues with stem girdling root and rots.
For more information, go to http://go.osu.edu/weedbarrier and http://go.osu.edu/landscapefabric.
McKinley is an Ohio State University Mahoning County Extension Master Gardener volunteer. Call 330-533-5538 to submit your questions to the plant clinic. Clinic hours are 9 a.m. to noon Mondays and Thursdays. Or visit go.osu.edu/mahoningclinic.