Weed control with black plastic

soeasytocraft Posts: 237 ✭✭✭

On my! The weeds and grasses got totally out of control last year because of all the rainfall. This year is a nightmare trying to control in natural ways.

I hear talk about using silage tarps for weed control. I understand the method but I have a couple of questions regarding these tarps.

#1 Where does a person get hold of them? What are names for them? My search has not been very forthcoming. I’m in Canada

#2 What are the implications to the soil? Such as how toxic are they to the food we plan to grow? I believe some are UVray protected. We are trying to be as organic as possible.

Please share your experiences and ideas. I am asking specifically about the tarps not digging methods etc. I have to lessen the labour load as we have a huge garden and don’t use a tiller.




  • KimWilson
    KimWilson Posts: 197 ✭✭✭

    Last year, the "paver" side of this picture was weeds that grew waist high. I have already fallen once breaking both left arm bones resulting in me now being a titanium "bionic woman". Since that traumatic experience was one that I did not care to repeat and the "paver" area is right outside of my back door, we came up with this method of weed control. Under the row of pots is ground cloth covered with gravel for drainage. The paver area is covered with ground cloth and then a layer of sand that was then covered with the pavers which are bordered by 2 X 4 wood. Thankfully, I have not had to weed the area even a single time all summer. On the top of the picture is an area that is covered in actual black plastic. I do not know what it does to the ground, but I have suspected that the fruits of the vining crops (winter squash and melons) are probably getting cooked from the extra heat absorption. It will be great if I am wrong in this, but I am thinking that I will be lucky if any of the fruits can survive. As you can see, I have many planted containers in this general area and have actually put some of the melons and squash on the top of upside-down 5 gallon white buckets to keep them from pulling on the vines and to keep them off of the hot plastic. I would love to have ideas of weed control that do not involve the use of any plastic, but have not been able to solve the issue at this point.

  • soeasytocraft
    soeasytocraft Posts: 237 ✭✭✭

    @KimWilson What a horrible accident you had! Recovery is slow and it’s never quite the same! Sure hope you are doing well now!

    Looks like you live in a rather hot place. We have a very short season of temperatures around 80. Some years it doesn’t get that warm. Nice you can grow in pots. We don’t have a great water supply and rely on our water collection system that is supplied by Mother Nature. So we have to plant in the ground where waters retained better. The weeds can be nuts! Hate to think of plastic ground covers but it might have to be a compromise. This year I’m the only one to manage it all and it’s rather overwhelming! So I’m seriously looking at options.

    I enjoyed seeing your garden area.

  • AngelaOston
    AngelaOston Posts: 247 ✭✭✭

    I put down paperbags and cardboard then worm compost and horse manure. Then about 6-8 inches of woodchips last fall. I now have an amazing garden with no weeding. And no till rich compost and retains water in heat.

  • soeasytocraft
    soeasytocraft Posts: 237 ✭✭✭

    @AngelaOston I love that method. We use it around the perimeter of the garden plots. We found in the garden when the chips broke down the soil became deprived of nitrogen and it took a couple of years to correct itself. When I researched this I came to the conclusion that it works better in some climates then others.

    You are so fortunate this method has been so successful. The wood chips were a huge disappointment in the garden but what a great edge around the garden

    We do use lots of manure and compost to amend the soil. Problem is we have a huge garden to feed ourselves and others all year long. The weeds get rather daunting. This is the first year to use a beautiful raised bed and find it’s been successful for a portion of what we grow. Little by little we might add more raised beds and that could be a great help.

  • Karin
    Karin Posts: 272 ✭✭✭

    The main thing we use black plastic here for is to kill off kikuyu grass. This nightmare stuff will grow from a teensy tiny piece of root and takes over everything. It sends out long runners underground to invade all the gardens grrrr. The only way to really control it is to cover with thick black plastic and weight down the edges well. This is best done in summer and the heat kills the grass, then it can be pulled up and removed.

    I have also used black plastic under strawberry plants to keep the soil warm so they will fruit earlier, also it helps stop some insect pests. But I don't like to use it much as I feel the soil goes dead underneath it.

  • JodieDownUnder
    JodieDownUnder Posts: 1,482 admin

    @soeasytocraft I'm definitely with @AngelaOston with her method, if you have access to those materials. Otherwise you could use old sheets of polycarbonate(laserlight) roofing sheets. I found this way quite by accident. While I was replacing the old hail damaged patio roof with laserlight, I left a sheet laying on the lawn and within 1 day, it had burnt the grass underneath it. I was upset with myself because it looked so strange, a large, square, burnt piece of lawn in a sea of green. Then I got to thinking how I could use this process to get rid of unwanted weeds and grass. I have been using this method now for years. The laserlight is very intense and you only need to keep it in place for say 5 days(in sunny weather) put rocks or bricks on top. I've even used roofing iron, needs to be down for longer but works just fine. So no chemicals, no nasty residues, stays damp underneath. A win, win situation.

  • Jannajo
    Jannajo Posts: 173 ✭✭✭

    @jodienancarrow ...well, that's easy...just find this: ah, polycarbonate -laser light- roofing sheets! Great!

  • shllnzl
    shllnzl Posts: 1,816 ✭✭✭✭✭

    Xeriscape landscaping in desert city areas usually involves black plastic covered with some kind of rock gravel. Holes are cut in the plastic for plants and sprinkler heads.

    Over time, dust accumulates in the rock. Then comes rain. Weeds DO grow in the rock, sometimes finding a crack in the plastic. Most of the weeds die after sustained lack of rain, leaving dried up plants to mar the look and maybe even produce more seed?

    It is not uncommon to see established landscaping with bits of plastic poking up through the rock. That is probably after at least a decade though.

    Bottom line: Weeds will find a way; all we can do is slow them down.

  • frogvalley
    frogvalley Posts: 675 ✭✭✭✭

    @jodienancarrow I love the laser light idea! Gonna try it.

    My black plastic story is not for the squeamish. Ions ago I was pregnant and living with my in-laws. My father-in-law tilled up a spot so I could have a small garden. At the end of the season, he put down black plastic to prevent the weeds from growing. At the very beginning of the next growing season, just a few weeks from my delivery date, I sat on the plastic to weed. It was so uncomfortable - all lumpy and bumpy. I would hit the bumps to flatten them out so I could scooch all along the 40'x60' garden. Once in a while, I'd reach under the plastic to get some weeds. After finishing that chore, I went to the house for lunch and my father-in-law suggested taking up the plastic. We all went down to the strawberry patch and started to systematically fold up the plastic. To our collective horror, those lumps and bumps I was hitting were snakes. There had been a snake party going on and every type of snake (including rattlesnakes) had been invited. It was only because it was so early in the season and still very cold outside that I lived to write this. I'm telling you, we've never used black plastic again. But don't let me stop you.

  • AngelaOston
    AngelaOston Posts: 247 ✭✭✭

    Oh i didnt know that could be a problem with the nitrogen. Learned it from paul guetche. The wood chip guy. Wh adds aged chicken manure in regularly. Its prohibited to have chickens in my neighborhood, so i add human pee ponic system. With aged diluted urine with plant bacteria and lacto bacillus. So i guess that adds in enough nitrogen. Im not having any problems, along with the worm compost.

  • AngelaOston
    AngelaOston Posts: 247 ✭✭✭

    Here is my wood chip garden in the former front of my house

    The soil underneath is pretty black and rich. Was dry there - with sparse viney ground cover.

  • Torey
    Torey Posts: 5,505 admin

    @frogvalley How absolutely horrifying! Snakes are a huge issue for me. We have some here, harmless garter snakes for the most part. But I won't be laying down any plastic now! Hadn't thought before about what might live under it.

  • AngelaOston
    AngelaOston Posts: 247 ✭✭✭

    I also have planters - that are working pretty well

    they are mostly five gallon bucket with 5 gallon grow bags on top with a hole on the bottom of the grow bag with a hydroponic basket. - i covered the buckets with burlap sacks. So wouldnt look so weird on my porch. But you can see some of them dont have the burlap bag anymore.

  • AngelaOston
    AngelaOston Posts: 247 ✭✭✭

    And then the latest is James Fry Revolution Garden system. This is working very even better than the other two.

    started it in early june with straggly starts from lowes and i. Six weels became huge.

    it also uses pee ponics in the nutrient pool that feeds the roots.

    Sorry the middle photo is my potatoes in grow bags. Also going well

    the top is the second week of june on the Revolution garden bed The bottom is the middle of july. About 5-6 weeks later.

  • JodieDownUnder
    JodieDownUnder Posts: 1,482 admin

    @frogvalley that is a Heck of a story. Glad you made it out alive. Anyone using the metal roofing sheets, be careful of the same predicament, lift, flip and scan. I've not come across a snake but hey you never know. The laserlight you can basically see them, depending on the shading bu still use caution.

  • Grounded
    Grounded Posts: 153 ✭✭✭

    Silage tarps are basically known as plastic/ polypropylene/ visqueen and are sold at most garden centers, big box hardware centers, through Amazon, at on-line seed and supply outlets. I saw online that silage tarps are available at Johnny's Seeds. I would therefore assume they would be available at similar sites.

    I also skimmed an article at notillfarmers.com which said that there are chemicals added to many plastics which may not be good for humans. They also said that the use of plastics can fry more than the weeds, namely some of the organic life in the soil, which is left somewhat compacted. For use on a no-till garden, depending on the quality of the soil, it might be counterproductive, although you could amend the soil with compost and mulch, you still have to find a way to combine the amendments with the soil itself.

    This won't help you now, but, I have seen on a The Grow Network video where you use intensive planting/growing techniques to have the vegetables grow to form a tight barrier leaving little to no room for weeds to grow.

  • ltwickey
    ltwickey Posts: 369 ✭✭✭

    I grew up with parents that loved using black plastic to keep the weeds and grass down. But as I got older I realized a few things...

    1. there were still weeds and grass growing underneath
    2. the veggies had an off taste to them

    So as an adult I turned to more natural methods. I have tried the cardboard method, but my favorite is to use muslin bags in place of the cardboard layer!

  • KimWilson
    KimWilson Posts: 197 ✭✭✭

    @soeasytocraft Thank you for your comments. I am doing very well. I had an excellent surgeon. One of my scars is not discernible. The other (right on my inner wrist) is probably a good 6" long, but it is straight, a good heal, and I do not have pain (even with weather changes). I live in northern AZ. We can plant usually right at the end of May. It does get somewhat hot here, rarely ever getting to 100 degrees, but the growing season is not what I think of as a long one.

  • KimWilson
    KimWilson Posts: 197 ✭✭✭

    @itwickey Do the weeds grow through the muslin bags? Where do you get them and how do you secure them to the ground?

  • KimWilson
    KimWilson Posts: 197 ✭✭✭

    That is horrible with the snakes. I think that my husband has a bit of a loss of hearing from being home when I happened to step across a snake that was just outside my front door. LOL!!!!!! Hardly ever scream, but made an exception that day.

  • annbeck62
    annbeck62 Posts: 994 ✭✭✭✭

    I've had success controlling weeds laying down newspaper and then wood mulch on top. The key is make sure the newspaper overlaps or the weeds will find their way through. It improves my soil rather than plastic which leaches into the soil.

  • marjstratton
    marjstratton Posts: 1,132 ✭✭✭✭

    I have generally put down cardboard from boxes. The trick is to get off all of the packing tape and other plastic before putting it in the garden. This year I think I will only put cardboard on the paths in my garden and then put wood chips (and maybe sand) down on top of the cardboard. I have a small cold frame with the clear roofing material on it. I think I'll try laying that flat on an area that I want to get rid of all the grass and see how that works. Thanks for the tip

  • marjstratton
    marjstratton Posts: 1,132 ✭✭✭✭

    I have heard that for "Lasagna gardening" with newspaper, you need at least 6 layers of newspaper to completely block the weeds from coming through. Then the wood chips or what ever on top.

  • thelinda
    thelinda Posts: 21 ✭✭

    I too had problems with snakes under black plastic and also in a raised bed garden that we created with cinderblock. The snakes I guess went in during the winter and kept warm. When I began to plant in the raised bed, little snakies came out. Fortunately they were not venomous and I was able to feed them to my neighbors chickens.

    There is black plastic and then there is landscaping fabric... Water doesn't easily penetrate black plastic, so you can damage your soil microorganisms if you leave it in place too long. Landscaping fabric allows water to go through and you can leave it down all year if you wish.

    In hardware stores they sell rolls of cardboard or heavy paper near the roofing area. You don't want anything toxic, so inspect it closely. I took a college Orchard class and the instructor said he used that. Like someone else suggested, old sheets and blankets, although a lot of them are acrylic and other manmade materials.

    After learning the hard way, I prefer biodegradable methods such as newspaper, brown paper, old cotton sheets from the thrift store, etc. Then once you get started, go with the lasagna method. It will be much less work and eventually you will notice healthier plants that consume less water.

  • Voodoo Flóra
    Voodoo Flóra Posts: 258 ✭✭✭

    @soeasytocraft weeds are a great friend, because it is mother nature telling you where a hardy plant will survive. Also, never forget a weed is what you make it. So many valuable plants have been classified as weeds. If you think it's a weed, then OK it's your land you decide. However, some "weeds" are actually valuable plants you may want to keep. Yet, if you decide you don't want the "weed" simply replace it with a plant of your choosing that will out compete it. Water only that very specific area of the new planting you created such that unwanted weeds do not have the resources to grow around it. Plants you don't desire in your garden are easily handled with selective watering and competition. I've never had to do anything other than this. If you did want certain places in your garden without any plants at all, I would place pretty stones and seashells in those spots. This is a far better remedy than plastics of any kind. Happy crafting!!! I like your name.

  • Mark Baker
    Mark Baker Posts: 19

    Between rows, I use heavy brown paper in large rolls that you can get from Amazon, covered with lots of straw to keep it from blowing away. It prevents weeds, holds moisture in the soil, keeps the soil cooler, lets you walk in the garden after a rain without getting muddy and is biodegradable. Growing beans, cucumbers, and small pumpkins on a trellis lets me mow close to the rows without hurting them. I am also experimenting with growing in translucent 55 gallon plastic drums, vertically for potatoes, and cut in half horizontally for lettuce, radishes, zucchini, etc.

  • ltwickey
    ltwickey Posts: 369 ✭✭✭


    If you put down a good layer of cardboard first, weeds do not get through that to the muslin layer. I like the muslin as it gives the roots something grow through and hang on to.

  • ceriridenour
    ceriridenour Posts: 52 ✭✭✭

    We tried the layer of plastic and the weeds just broke through it. Cardboard worked better for us and it is also biodegradable.

  • VermontCathy
    VermontCathy Posts: 1,920 ✭✭✭✭✭

    I'm of two minds about this. Black plastic "mulch" is going to be more solid than an organic mulch, and harder for weeds to break through. It will definitely warm up the soil underneath, which is a good thing in Canada or Vermont, but a problem farther south in warmer climates.

    I have avoided it so far, preferring to use a mix of mowing (in the walkways between raised beds), hand-weeding (in the raised beds), and a few inches of leaf mulch (in the raised beds around tall plants such as potatoes, garlic, etc.)

    If you have a problem with low rainfall, you may want to try *sunken* beds, the exact opposite of raised beds. Dig a trench in your regular soil, break up the soil, and add amendments, but leave the top of the soil at least 3 inches below the normal soil level. Water will drain into the bed instead of out of it, and it will hold moisture better during dry spells.

  • Sheila
    Sheila Posts: 106 ✭✭✭

    We have used a variety of materials to keep down weeding in the garden. If you can locate used natural carpet (wool, jute is great) it works for a number of years. We use it between the rows on the paths and to border the Raspberries on each side. We take it up each winter and just roll and store in an open shed til the spring. We have also used straw and hay (from organic farms) that has been left out for a year or two to sprout any seeds left in it and that prevents the addition of plants that need to be pulled! This we just tilled in at the end of the year. But the main component to it all is a good thick barrier that you are comfortable with.