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Growing Under Plastic Sheeting


In December I prepared various beds, weeding manuring etc... then, I sheeted them up with black 1000 micron visqueen.

Today when I pulled back the sheeting there was a carpet of fine weeds happily growing underneath the sheeting.

I presumed black sheeting would surpress them but that has not happened.

Why is this?

Any help appreciated



  • BobTheGardenerBobTheGardener Posts: 11,384

    Many will have recently germinated from weed seeds in the soil because the sheeting has helped warm the soil up.  Others will be perennial weeds like dandelion which start coming up at this time of the year.  Because they will be unable to photosyntensize due to lack of light (I presume they are mostly white/yellow in colour?), they will die as long as you leave the sheeting in place.  To kill all weeds using weed suppressing membrane, you may need to leave it in place for a whole season.  As soon as you plant anything or turn the soil, dormant weed seeds will be brought to the surface though, so membrane is not a panacea.  There's an old gardeners saying that goes "One year's seed is seven years weeds." which is effectively how long it takes of diligent weeding before an area is as weed free as it is possible to make it.

    If you have plants ready to go in, I would suggest making slits in the sheet and planting through it for now.  You could hide the sheet with bark chippings for the time being.  Keep peeking under the sheet and when the ground is clear later in the year, remove the bark and cut the rest of the sheet up (so you don't damage anything you have planted) to remove it.

    A trowel in the hand is worth a thousand lost under a bush.
  • nutcutletnutcutlet Posts: 27,415

    I tried that years ago and the mice/voles/rats  that undermine our garden had a great time eating the spuds and other roots.

    I think we have to live with weeds. I drive along our road in late summer and seeds from assorted compositae are drifting around. They're part of life.

    In the sticks near Peterborough
  • BobTheGardenerBobTheGardener Posts: 11,384

    I agree, nutcutlet.  It is useful to help with the initial clearing of a badly weed infested patch, but hand-weeding will always be necessary and is the best way.  I especially don't agree with the permanent laying of membrane as some councils and builders do as it just goes against nature, ruining the soil and natural soil ecosystem (eg starving worms for a start.)  I much prefer using a good depth of mulch as this suppresses weed seedling germination and the perennial weeds are easy to see so can be removed as soon as they poke their heads through.  A mulch will also feed the soil with little need to provide any extra feed. Win-Win.image

    A trowel in the hand is worth a thousand lost under a bush.
  • Bob,

    Correct they are spindly white stalks with a yellow head...


    Thank you



  • DovefromaboveDovefromabove Posts: 87,852

    There's a lot to be said for one of these and now is the perfect time to use it image

    I like to pop out into the garden in the early morning and spend half an hour just slicing those weeds off as they peep through the soil image  Very therapeutic image

    Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.

  • marshmellomarshmello Posts: 683

    Absolutely Dove.

    I couldn't garden without mine.

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