New Landscape Fabric in a Tree Lawn
Homeowners are being sold acres and acres of landscape fabric in our area this spring. Maybe they are looking for an easy way to cover their landscape in a year with watering restrictions, figuring that a no-water-needed configuration of landscape fabric and mulch is the best alternative to turf. Or maybe they’ve just been fighting weeds in an area for so long that just covering it with something seems the ideal solution.
Landscape fabric comes in a seemingly endless variety of weights, thicknesses, and synthetic materials (mostly plastic). Sometimes it is called weed barrier or weed blocking fabric. After moving into my house over twenty years ago, I discovered what was probably the original “weed-blocking” fabric, a layer of black plastic bags under river rock in my tree lawn (the area between the sidewalk and street). Edges of the plastic showed between rocks, and big tall weeds thrived! Once we decided to remove the rock-and-plastic landscaping, just under the plastic we found a layer of roots from the green ash tree that lives in the tree lawn. The soil was bone dry, and the roots were doing their best to search for needed water.
In modern landscape fabrics, thicker plastic is one of the options available. Some are completely nonpermeable, while others claim to have channels to allow “air, water, and nutrients” to penetrate. They are not made from recycled materials and usually are not recyclable. Other more permeable options are available, usually being made of polyester (some products do not even say what they are made of!). These are somewhat see-through and may stretch a bit when tugged.
The marketing for these fabrics promise attractive, weed-free landscapes. In truth, it is not long before dust, soil, and fine mulch debris accumulate on top of the fabrics, creating a perfect seedbed for any weed seeds that blow in. Additionally, the fabrics create a perfect, smooth runway for mulch to blow off of in high winds or to run off of in heavy rain. Rarely do I see a landscape fabric-and-mulch area that doesn’t have patches of the fabric showing through or edges of the fabric rippling above the mulch.
New (Less than a Month Old) Landscape Fabric and Mulch Installation
Older Landscape Fabric and Mulch Installation
Landscape Fabric Showing Through Rock Mulch
Colorado State University Extension absolutely does not recommend polyethylene landscape fabric. Even those plastic fabrics that claim to have a system to allow some water and air through don’t let enough through to prevent run-off in a heavy rain, and they don’t allow surrounding trees to receive enough water. Additionally, CSU doesn’t recommend landscape fabric under organic (like wood chip) mulch because the mulch will stay in place better if it is in direct contact with the soil (although homeowners will have trouble keeping wood chip mulch in place in high wind areas, regardless of whether landscape fabric is used under it). Also, organic mulch can slowly break down and add organic material to the soil if there is no barrier between the two. They suggest that if an area is mulched and weeds are still a problem, the mulch is not deep enough. If a temporary weed barrier is needed in a newly cultivated or planted area, a two-to-three sheet layer of newspaper under a three-to-four inch layer of organic mulch is recommended since it will suppress weeds, and the newspaper will usually break down within a year. Cardboard is not recommended in our area because of the arid climate – it will be years before it breaks down and the soil underneath it will stay far to dry to support healthy microorganisms and to desirable plant roots, including tree roots.
Impermeable Fabric Around Young Shrub
Unfortunately, this is another case of “if it seems to good to be true, it is.” Covering our ground with artificial materials just isn’t the best route to an attractive, low maintenance landscape. Start by eradicating the weeds that are already in the area you want to cover, cover with newspaper if you want a barrier, then cover with a thick layer of organic mulch (if the area is very windy, you may need to go with rock over bark or chip mulch). You’ll be happier in the long run than if you spend good money on fabrics that rip, show through the mulch, and encourage new weed seeds to germinate in a fairly short amount of time.
Contributed by Carey Harrington, Certified Colorado Gardener and Colorado Native Plant Master
References and Additional Resources:
CSU Extension Master Gardener Note #245, “Mulching with Wood/Bark Chips, Grass Clippings, and Rock” – www.cmg.colostate.edu/gardennotes/245.html
CSU Extension Fact Sheet #7.214, “Mulches for Home Grounds” – www.ext.colostate.edu/pubs/garden/07214.html
Pikes Peak Area Garden Help 
June 23, 2014 at 12:09 am
This seems to refer to landscape ‘fabric” that is primarily a plastic barrier. I was looking for an article on landscape fabric that is more like a fabric that would appear to allow in air and water, and also small roots.
June 23, 2014 at 10:08 am
Actually Jill, this article does refer to the very type of fabric you are asking about. I don’t even consider solid plastic to be a “landscape fabric.
October 7, 2014 at 1:59 pm
Hi just wanted to give you a brief heads up and let you know a few
of the images aren’t loading properly. I’m not sure why but I think its a
linking issue. I’ve tried it in two different browsers and both show the same results.
August 10, 2015 at 5:14 pm
I have almost lost my mind…..at 66 I am trying to undo what I did almost 20 years ago when I laid down plastic and mulch…I have been pulling up the plastic as best I can. Is there an easier way to do this like with a dethatcher or something similar?
August 10, 2015 at 5:47 pm
Oh Susan – I wish I had some good ideas for you, but I think it just comes down to the hard work of raking the mulch aside and lifting the plastic (or possibly hiring some help!). When we first moved into our house, we had to remove old black plastic topped with river rock and the plastic was quite brittle and kept shredding. I still think it is one of the hardest tasks we’ve ever tackled. Good luck!
January 14, 2016 at 8:11 pm
I bought a house in aug. The previous owner had soil laid out, then black plastic laid over it and another layer of soil over that to read grade around the foundation and run water away from the foundation.
I cannot stand plants and want to put brown/tan/gray river rock down this spring. What is the best way to do this and not reverse the work done to keep water away from the foundation? Thanks.
January 19, 2016 at 2:12 pm
Hi Erik – If you are having trouble with water collecting around the foundation, you may need to consult with a landscape architect or other professional to see what the easiest/best solution is. If there is no trouble and you are just wanting to add the river rock, there isn’t any reason you couldn’t just add it right on top of that top layer of soil (unless you are worried the final level would be too high). No need to put landscape fabric under the rock. Hope this helps.
February 7, 2016 at 9:42 am
We have a very large area that 20+ years ago we had landscapers put down black fabric and plant shrubs and plants. We get weeds terribly so we are having everything taken out and river rock and some new plants and very small shrubs put in. We have had crawl space/water problems and have had to spend a fortune on our crawl space 2 to 3 years ago. Hopefully that is all fixed now. Some of the problem was people who layed mulch piled it up against the house. I am at my wits end trying to decide whether to use fabric or visqueen (which I probably spelled wrong). I do NOT want weeds but I don’t want drainage problems and I want the plants and shrubs to grow healthy. This area is on the north side of the house so gets some sun but not all day sun and is in Indiana if that makes a difference. What would you suggest.
February 8, 2016 at 11:29 am
Hi Carol,
The crawl space work doesn’t sound like it was much fun – not sure exactly what was done though. Mostly interior work? Grading the soil away from the foundation seems like it would have been an important part of stopping water from seeping into your crawl space. Gutters are another part of the solution too.
Landscape fabric is not meant for waterproofing your foundation (or anything). Properly graded soil, gutters, not piling mulch (or soil) against the foundation are all places to start. If you still have drainage problems, you may need to look into having something like a French drain installed ($$$). And as I’ve written above, the fabric won’t do a long-term job of preventing the weeds (as you saw with the black fabric you already had and removed) – eradicating any existing weeds and then using thick mulch is still your best option for weed prevention (still will need to do some light hand weeding at times).
It might be best to contact a landscape architect or designer in your area, as she/he will be better equipped to give advice when they see your actual situation. Many are willing to do consultations by the hour (around here, that runs about $75 per hour).
Good luck!
April 2, 2016 at 2:08 pm
first off you obviously havent dug down far enough. thise spits showing are clearly high spots and look to be level witht the outside ground. with a proper depth dug and secure edging around the fabric i doubt youll see those same results
April 15, 2016 at 11:04 am
But you will still get dust, soil, and mulch debris accumulating on top of the fabric which will make weed seeds quite happy. So then what is the point of adding a “weed barrier”? I agree that landscape fabric is a huge mistake. You’re better off spending the money on a thicker layer of mulch or gravel.
April 26, 2016 at 12:37 am
I think good quality fabric has its place, what i see lazy people do is spray the crap out of the sod with roundup and then just dump mulch over it. At least the fabric is not putting poison into the ecosystem.
I have used good quality fabric and guess what the soil underneith does not dry out and as long as you pull the weeds that do start it’s much easier to pull them as the roots don’t penetrate the fabric for a good amount of time.
You also don’t need as much mulch and who cares if some blows off if it gets windy? You generally refresh it every two years anyways.
Mulch is not difficult to move around, believe me I had rocks with heavy black plastic and that was a nightmare compared to mulch.
So while the fabric may not be needed it certainly does not hurt if a good quality product is used and does male pulling weeds way easier, sorry but it does.
May 24, 2016 at 12:15 am
Actually, landscape fabric is not intended to merely discourage weeds. It acts as a barrier between soil, and decorative rock mulch . Rock can be very expensive, depending on type. The Landscape fabric keeps it from disappearing into the soil forever.
Yes, it does need to be replaced, eventually.
Black plastic should NOT be used under rock. The rock must be deep enough to hold the fabric down, and When installed properly, fabric cannot be detected.
Also, avoid walking in the rock in planting beds ( use stepping stones) to avoid shifting , and extra soil compaction.
Really, a professional installation is best.
April 10, 2017 at 3:29 pm
Would two layers of burlap work as a barrier between black soil and white marble chips? I have a small yard/garden that already has a mix of large gravel, pea stones and black soil all mixed together under flagstone pavers. I wanted to clean it up and thought white marble chips would look nice. The yard is almost completely in the shade of a large cedar tree, so planting isn’t really an option. Thanks.
April 11, 2017 at 8:28 am
Hi Suzanne,
I have to admit I’m not sure what “black soil” is (or are you just referring to the color and not wanting it to mix with the white rock?). The burlap probably would not hurt anything. If you are wanting it to suppress weeds, that may work for a short period of time. As happens with other rock mulches, soil and dust and debris will blow in (and, in your case, juniper/cedar debris) and eventually make a bit of a seed starting base for weeds. Given the shadiness, this might take longer unless you have some vigorous, shade loving weeds. Good luck!
June 14, 2018 at 3:34 pm
I would advise not to be so negative concerning usage of landscape fabric. In fact, it lets water and air in and doesn’t destroy the soil. Second, it looks pretty good, especially with mulch or stones over. For sure, you should replace it from time to time because, otherwise, you’ll see all the shortcomings described in the article. However, if you replace it in time, you enjoy your weed-free garden. BTW, at my blog, I shared my experience concerning the choice of landscape fabric https://gardeningadviser.com/