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weed supressing membrane

Does anybody know how long weed suppressing membrane has to be in position to kill and established lawn stone dead? I would imagine at least 6 months, 1 month has been suggested. I can't find written documentation on the test being actually carried out. 





  • Gold1locksGold1locks Posts: 498

    I have read your earlier posts and understand that you don't want to use glyphosate. I would think that a totally obscure material such as black polythene would kill your grass in around a month or two, though some aggressive grasses such as couch could take a lot longer. Weed suppressing membrane is different. I have just checked  my own (in the shed!) and it does let some light through ( as well as moisture of course), which means the grass could take a lot longer to die, but I have no idea how long that might be. 

    If you have perennial weeds such as dandelions, they will take a lot longer to die. They survive underground every winter! 

  • CalendulaCalendula Posts: 69

    1 month is certainly not long enough, and in my opinion it will never kill an established lawn 'stone dead' on its own. I used it on very lush grass on my allotment, but it only kept the light out to weaken the top growth. I still had to dig out all the roots to stop them resprouting. Once your ground is weed (or grass) free membrane will help to slow regrowth, but don't rely on it to kill the lawn altogether.

  • jspjsp Posts: 59

    Thanks Calendula that's useful to know. You haven't tried a flame gun have you? That's my other option. (sorry to partially duplicate threads, but the other one got very sidetracked.)



  • nutcutletnutcutlet PeterboroughPosts: 26,878

    What are your intentions for the ex lawn Jennifer? If you want to garden it I'd slice the turf off and dig it over. Turf can be composted and replaced in time. Weed surpressing membrane is more about stopping weeds coming up through gravel, bark etc than killing them. As Goldilocks says, they're not light proof.

    The slice off and dig method has the advantage of now rather than waiting. Anything like twitch or other persistant weeds would still be lurking when the grass had gone and you could be getting on with eliminating it. It's not difficult in an empty bed, it's when it's round all your precious plants that it becomes impossible.

  • artjakartjak Posts: 4,167

    Turf, when rotted down produces 'loam' as far as I know, which is a highly desirable product.

  • jspjsp Posts: 59

    I actually just want to replace super-fast growing grass with slow growing grass. I am all organic so it's light exclusion or flame gun. I'd be keen to hear from anyone who's used a big propane or paraffin flame gun. I'm an experienced gardener with a degree and PhD in Botany, so not a novice. I don't need other peripheral suggestions. I just would appreciate concrete information from anyone who's actually tried to kill a lawn organically, especially by the above methods.  

  • nutcutletnutcutlet PeterboroughPosts: 26,878

    I have a flame gun

    It burns off top growth, 



  • jspjsp Posts: 59

    Hi Nutcutlet, Does the top growth burn off quite quickly, if you get it after a week of dry weather? I gather that I do a first pass to take the cuticle off, and then go over it all again to burn the withered foliage off completely.  Is that what you do, and is it reasonably quick? Thanks! Jen

  • jspjsp Posts: 59

    Well, I've bought a roofers flame gun and flamed my lawn. It was quite easy, and just wanted a lot of health-and-safety type care. The grass turned brighter green as I flamed it, and now looks slightly blackened, but not burnt. I'll post if there is any progress in the coming days.

  • jspjsp Posts: 59


    This flame technique has been very good. Immediately after I finished flaming the lawn the first time, our very bad hayfever (of 2 years) vanished. The next day the lawn looked kind of tan in colour, the way that it does in a really hot dry summer. Today I went out and flamed it again, to try to finish the grass off. It was harder this time, because the gas cylinder was running low. The first time the job was just as quick as strimming. I'm very glad I used the technique, because my toddler was able to play out on the grass as soon as I was finished. There has been no need to wait for rain (which almost never comes here) and no need to worry about the 60 day half life in degrading glyphosate. Just a nice, slightly toasted look to my lawn, and no more hayfever. Huzzah! I'll keep at it and figure out just how long it takes to actually finish of the grass. I need to do that before I can replace it with slower growing lawn seed. It seem that I accidentlly sowed fast growing grass that is mean for livestock farms, and I am trying to switch back.

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