Getting rid of Couch grass

Discussion in 'Planting, growing, nurturing Plants' started by Chris Willis, May 3, 2012.

  1. Chris Willis

    Chris Willis Junior Member

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    I have couch grass all over my back yard, even though we had it levelled at one point getting rid of all the surface problems we had....pebbles for paths, lawn etc....but it has all grown back. I have been wanting to lay out hay to start no dig gardening but I fear the couch will still keep on growing. Is there a green way to get rid of this awful stuff as I don't want to use chemicals to get rid of it? Any help you can give me will be gratefully received :)
     
  2. Grahame

    Grahame Senior Member

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    You probably need to look at this as a long term war Chris, with a many layered approach. My experience is that some of the most important weapons are vigilance, persistence, attention to detail.

    Some of the things to consider include the old newspaper and sheet mulch technique, ensuring that the edges are subject to a tight regime of perimeter surveillance.

    I have also found that when I built up the organic matter to very high levels it is easy to implement the above mentioned techniques.

    Other options (not personally tested) include out completing them with either heavily sown turnips or tomatoes. I have a feeling I once hear PP say that he had used a heavy cover with pigeon peas?

    I'm sure there are other techniques too.
     
  3. adiantum

    adiantum Junior Member

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    Not quite sure what couch grass is but I envision a rampant running grass that will resprout from every piece of cut rhizome. The equivalent for me is Bermuda grass. Only digging out the entire soil volume to a depth of half a meter and screening it for any bits of root, then replacing it behind a stout and continuous edging serves to completely exclude it. Any other strategy will only result in temporary control, not eradication. Confined pigs and chickens for months at a time, entire summers under plastic to heat the soil, and weekly tillage for a season....still it comes back eventually. I think that a very long rotation would work....more like a swidden or shifting cultivation, in which badly infested areas are allowed or encouraged to grow up into thicket and even young forest for some time....enough for the shade to subdue the grass before being cleared for planting again. But the technique of paper and cardboard mulching every year, with planting of transplants through the mulch layer, will pull off one crop at least of annuals each year. Stout transplants like tomato or sweet potato seem to work best. The other option, of course, is to USE the problem grass as a resource. Bermuda was originally introduced for warm-weather grazing and hay, and it is excellent for these purposes....
     
  4. S.O.P

    S.O.P Moderator

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    Bermuda is Couch so everything you said is relevant.
     
  5. Raymondo

    Raymondo Junior Member

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    I sheet mulch and eliminate couch.

    1. Dig a small trench around the area you want cleared. This is important so you can monitor and eliminate intrusions. Couch will intrude. This is a permanent feature.
    2. Cover with wet newspaper. I'm talking virtually entire newspapers. Couch will simply grow through anything less. Make sure they overlap by about half. Put whatever organic material you want on top. I've used straw, wood grindings and grass clippings.
    3. Wait, and while waiting check your perimeter from time to time for attempted incursions. I find that after a year most of the couch is dead. Some will still grow through. Remove it carefully and thoroughly.

    Most of my garden beds were created this way. They do not have couch. I still have to monitor the edges, and check for any seed grown plantlets.

    I have also created beds using weed mat instead of sheet mulching. I prefer sheet mulching because you can plant into it immediately in pockets. With the weed mat, you can't plant until you take it off after a year or so. And lastly, I have created beds by removing 15cm or so of sod, forking open what's left, then piling on the organic matter.

    All three methods work, though the last is heavy work on my sticky clay soils. Sheet mulching is definitely worth considering.
     
  6. gardenlen

    gardenlen Group for banned users

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  7. pebble

    pebble Junior Member

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    Make friends with couch. It's really not such a terrible plant, and its only doing what it is meant to do (cover up bare ground). Sometimes hating something or fighting it just makes it stronger. Couch makes great compost/soil (hot compost! or very long term compost, and in its own compost)

    I've also had success with putting down a layer of cardboard and newspaper. I've never had any problems in those kind of beds. You need to get the layers thick enough, and overlap heaps so no light gets in (err on the side of caution). Sometimes I build beds straight on top of that, other times I've simply covered the bed with something dark and left it for six months. Neither are ideal ways of creating garden - they both exclude water from the soil beneath, which must be detrimental to the soil ecology, so it's not something I would want to do repeatedly.

    It's really important not to dig once you establish beds this way - digging exposes roots to light and then they will grow again. So if you want to grow annuals, you need to buid raised beds. If you are growing perennials, you can build some garden on top and then keep it well mulched.

    I find that in beds that have couch in them already, that a good weed, followed by heavy mulch was the way to go. A bit more couch will come up (because the mulch isn't light-proof), but because the couch is growing in such a deep, soft, moist bed, it is very easy to pull out, and just becomes weeding like any other kind of weeding, instead of a Big Problem.
     
  8. gardenlen

    gardenlen Group for banned users

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    should also have said you need to create weed barrier around beds app' .5 meter to 1 meter wides same process lay thick paper overlapped with bed paper then mulch it or pebbles whatever, this zone is where you deal with the couch, this zone also widens you mycrozoria helpful zone around the beds.

    len
     
  9. Chris Willis

    Chris Willis Junior Member

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    Hi Len, thanks so much for your kind help with my devious grass problem. I so wish I had seen your site before buying some very expensive raised garden beds...I think the straw bail raised gardens would have given us a lot more room to grow stuff as well. Although I've always enjoyed gardening, as I have aged my back has screamed at me to stop gardening....and I did for a while. I have not been a vegie grower before, but realise now what I've been missing out on. There's not much I can do about the garden beds we now have, but through kind people like yourself and this wonderful permaculture web site, I'm learning so much. I am truly grateful....just a bit frustrated that I didn't learn all this stuff years ago. Never mine....onward and upward :) Cheers
     
  10. Chris Willis

    Chris Willis Junior Member

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    WOW!! You have given me some hope that maybe I can get over this problem....thank you very much for your knowledge on this curly matter. I have begun potting seedlings in large pots to try and get the maximum use of what garden I have. I do have 4 raised garden beds and when we first put them into the garden there wasn't much in the way of couch growing as our son had used a bob-cat to get rid of the rubbish growing and old pathways. It didn't take long before it became established again though. Silly me for letting it get hold....but with a back that gives me jip I wasn't prepared to get down to weeding it out. Thanks again for the knowledge
     
  11. pebble

    pebble Junior Member

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    Len's website is a real treasure.

    I'm a bit confused now Chris. Is the couch IN the raised beds? That's a different proposition, depending on what you mean by raised beds and what they are made of. The key thing about couch is to exclude all light (and not to dig again). Edges are the trickiest thing to exclude light from - obviously a flat straight edge is easier than a crooked one, or one that is bumpy.

    What's your climate like? I've lived in dry or coastal wet, cold climates. Don't know what happens to couch in the tropics.
     
  12. Chris Willis

    Chris Willis Junior Member

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    \

    Oh, NO!!! I have confused yet another person....so sorry about that. I live in Perth, Western Australia and we have extremely hot summers that seem to go on and on forever....hot weather can start intermittently in November and can often carry on 'fairly' hot (again, intermittently) until way into April. Very dry conditions and fairly windy too, at least where I live it is. The garden beds we use are made from Colourbond corrugated metal and stand almost waist high, due to my bad back. They have curved corners, and look like a long oval shape. When they first arrived I laid down heaps of newspaper and then covered it over with a lot of the rocky rubbish my son had removed with the bob cat (I suppose there could have been couch roots in it)....I did this mainly as it would have cost a kings ransom to fill them with good quality soil, so it was pretty much rubbish up to half way. I thought that would kill off any couch that may be lurking there. For the first year everything was great.....but then the couch began to surface, both outside the bins AND within them....which totally confuses me since I'm sure no light could have got through. I have dug down as deep as I could without upsetting any plants, to try and get as much of the grass out as possible. I mulch over with Pea Hay quite thickly. Thanks for your help....it is invaluable :)
     
  13. pebble

    pebble Junior Member

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    Don't worry, I am easily confused ;-)

    That makes sense though. It sounds like the couch in the bottom of the beds has surfaced. Or the topsoil you bought in was contaminated?

    How bad is the couch exactly?

    Maybe you could dig out the topsoil, put down cardboard etc, very thick and then fill with layers of soil building materials (like Len's beds, or lasagne gardens). The main problem is going to be stopping the couch from growing up round the edges of the cardboard, so you'd need to cut it to a tight fit I think, or find some way of pack the edges between the cardboard and the corrugate.
     
  14. adiantum

    adiantum Junior Member

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    Raised beds with any kind of edging are the worst thing where there are running weeds like bermuda (couch) and nutsedge. The roots get up next to and under the edging and there is no way to sheetmulch over them or pull them out and they will always be recolonozing from there. Mounded beds can be fallowed with a few months under paper (I'm already wondering where I can find massive amounts of newspaper, as one person above says it is better than cardboard if applied thickly enough), but there is no way to evenly cover both the bed and the pathways of any edged raised bed system....
    Principle...design needs to remain aware of the scale of permanence....often we do things that are too permanent (like the raised beds) for their purpose, or else not permanent enough (like me simply not sheetmulching heavily enough, and so imagining that couch needed it annually and could never be eradicated thus)
     
  15. pebble

    pebble Junior Member

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    That's a great explanation. I was wondering if the corrugations are running horizontally, then there might be a way to use that (vertically would be much harder).
     
  16. Chris Willis

    Chris Willis Junior Member

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    Yep....the corrugations run horizontally. I'm looking forward to reading what ideas you have. :)
     
  17. gardenlen

    gardenlen Group for banned users

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    the corrugations would be horizontal as the sheets will be if possible ordered in 6 meter lengths with 1 meter cut offs for the ends, 6mX1m good size for a bed. trying to source second hand sheets which may of course be as short as 3 meters?? see what happens. plan on using galvanised star pickets they are thicker grade steel as well. and construct a cover over the gardens using white mesh poly type design might be too expensive and too high for us.

    again we will develop good weed barriers, between the beds will be easier, this time make those barriers which will be the paths a meter wide. that way just like in the bale garden we did where the bales became the weed barriers app' 1/2 meter wide we dealt with the couch and Kikuyu in the barrier so then it did not make the beds, and as it was growing in the mulch that formed the barriers it was easily pulled.

    our big issue is filling teh beds initially to a height that allows us to garden, we have pile of pushed over trees to use as in hugelkultur and lots of top soil over burden from house site which is currently growing tall stuff like johnson grass and sidratusious(spelling) that we are currently harvesting and storing in sheaves(greens) to be laid on top of the timber (browns) before some top soil and some soil with mulch mixed in (accidental) which we are burying our kitchen scraps in, once that is all in then the mushroom compost and plant, hopefully by next season.

    logs and fire wood that are usable will be available free for the taking, apart from what we may keep, got chook pen to build yet as well, planted around 3 dozen trees so far around 70% are natives. got a small area we can have for bird habitat.

    any of those grasses will grow in under and up the sides, this is why the path/barriers need to be in place with the raised beds at the beginning.

    https://www.lensgarden.com.au/straw_bale_garden.htm

    len
     
  18. Raymondo

    Raymondo Junior Member

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    If it were me, I'd be establishing and maintaining a couch free zone around each raised bed, or if the configuration allows, around the lot. There are a number of ways this could be done. You just have to figure out a method that suits you. As adiantum mentioned above, unless you do this the couch will always be recolonising and efforts at removing it from the raised beds waisted.
     
  19. pebble

    pebble Junior Member

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    If the beds are waist high, do you really think it is being colonised from below and outside?

    Chris, along the straight edge will be easier (not sure about the curves). I would experiment with putting cardboard horizontally between the soil and the steel and then folding the cardboard over onto the soil (did that make sense?). Maybe a long piece of timber or steel to hold the cardboard against the steel in the groove of the corrugate? Then put lots of cardboard on the top of the soil, and build your beds on top of that. Big, thick cardboard that still has enough flexibility, and well overlapped. You could also consider something permanent like black plastic sheet (although I generally would rather eat the stuff than recommend it in a permie situation ;-) ). The cardboard will eventually break down, but in your dry climate that might take a while.

    I'm sure you can come up with other solutions, and the right one. Being able to look at the bed and see the actual spaces and curves etc will give you some idea of what can be used to exclude light.
     
  20. labradel

    labradel Junior Member

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    my garden area was very heavily infested with couch grass when i started it i have now all but gotten rid of it (the garden is a 15.5m circle ) by using chooks housed in a strip/ring pen around the of outside the vegie garden as a barrier to out side incursion with lots of persistence and very large quantities of mulch (paper,grass,cardboard ) LOTS of persistence and time .
     

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