Return to the Professional Gardener Forum | Post a Follow-Up

Plastic sheeting as weed barrier?

Posted by rkent 10b (My Page) on
Sun, Jan 23, 05 at 10:21

I am going to be clearing out a 4' wide strip around the perimeter of my house and putting down decorative rock and stepping stones. I won't be planting anything, using an ocassional potted plant instead. I have a roll of 6 mil (heavy) plastic sheeting on hand and wonder whether it could be used as the weed barrier beneath the rocks/stones. Or would mildew, mosquitos and/or other problems arise from the lack of drainage? Alternative suggestions appreciated as well. Thanks in advance...

Follow-Up Postings:

RE: Plastic sheeting as weed barrier?

In theory with regards to drainage a landscape fabric would be a better choice .. the best are fabrics contain herbicides that supposed to last for a long time. I don't like the sheeting in regards to drainage unless ofcourse you add holes.

In reality the material below the rocks will NOT keep weeds away ... and in time the material works it way to the surface and is a big pain in the butt. The best thing you can do is keep the area dry and well drained and plan on some regular weed control.

Good Day ....

RE: Plastic sheeting as weed barrier?

  • Posted by Ron_B USDA 8 WA (My Page) on
    Sun, Jan 23, 05 at 16:16

A smooth, even slope, adequate to sheet off water would be needed to prevent puddling. And sticks and rocks possibly able to poke through the plastic some day must be cleared away (laying it on a bed of sand might preclude this).

Rocks placed above plastic must be deep enough to prevent sun from photodegrading the plastic. Also important to keep spilled/washing soil, organic debris from accumulating among rocks and forming a substrate for weeds on top of plastic.

A large, broad area of plastic placed over roots of existing trees/shrubs might cause them some grief.

RE: Plastic sheeting as weed barrier?

Over time, debris blows in atop decorative rock and weeds grow. Some landscape fabrics are supposed to contain copper and have herbicidal activity but their long-term performance is a question mark. Ordinary plastic sheeting might well cause drainage problems.

If you use plastic, it is to be hoped that if you ever sell your home, the disclosure of defects would include the poor quality, compacted and slimy soil beneath the decorative rocks and plastic.

RE: Plastic sheeting as weed barrier?

  • Posted by clfo z7 with luck (My Page) on
    Sun, Jan 23, 05 at 22:05

I have been on several properties where both plastic and landscape fabric have been used under either rock or mulch, and both end up looking ratty. The plastic mulched area often has mold/slime growing in and among the rocks or mulch because there is no drainage. All ends up poking through the mulch material in tattered ends, and the weeds are perfectly happy to germinate on top of these materials.

I have found that a great alternative is thick layers of newspapers, laid down with the edges overlapping, and covered with bark mulch. If the initial layer of mulch is four or five inches thick, a layer of two inches applied each year in the spring keeps weed seeds from germinating pretty effectively. There will always be the occasional weed to pull, because plants will find a way

RE: Plastic sheeting as weed barrier?

Hey rkent
I notice you live in zone 10. Fabric is totally out of the question since you live in such a warm climate. Weeds will definitely grow up through or roots of weeds down through that stuff. Someone mentioned earlier that if you intend on leaving your plastic down for a while, cover it completely and thickly due to UV degradation. Also, do not allow any build-up of material to accumulate under the rocks otherwise, weeds will grow in it. Yes, it will get moldy under there. Also, some good advice above. Build this set-up on as a severe slope as you can to help avoid build up and, help promote drainage.

RE: Plastic sheeting as weed barrier?

Plastic stops water. It stops decayed small debris from leaching down.

Fabric is better and does not look bad if the gravel or rock is deep enough.

If there will be active kids or dogs and the gravel is finer, you need to dig "V" shaped slit trenches (very narrow) to tuck the edges down into - then fill with a bit of sand or gravel to hold. That will keep the sides of the fabric sheets from getting raised. It's the pits when that happens and rock gets under the fabric.

 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!

Return to the Professional Gardener Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.

Learn more about in-text links on this page here