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Carboard mulch question

I just moved to a new home in Minnesota and I'm planting some bulbs in a new raised garden I built. I'm planning on laying cardboard followed by a layer of bark mulch on top of everything after planting this fall. I'm wondering if I need to cut holes in the cardboard to allow the bulbs to grow in the spring, or will the cardboard decompose sufficiently over the coming months to allow growth in  the spring without cutting it up? Thanks


  • KT53KT53 Posts: 4,507

    A lot will depend on the type of cardboard.  If it's corrugated packaging it might take a while to break down fully but wet conditions over winter would probably be enough to soften it for bulbs to be able to push their way through.  Some corrugated cardboard does have a coating on it and that probably would not be suitable.

  • treehugger80treehugger80 Posts: 1,924

    just remember to remove any packaging tape as that will never rot.

    In the past I saw a patch of daffodils lift and tip over a pot that had been left accidentally on top of where they were growing, so wet cardboard shouldn't be a problem!

  • Levi3Levi3 Posts: 2

    Mike, what else would you suggest? I've heard cardboard is a good weed barrier that also improves soil quality when it decomposes. I'm open to any suggestions, thanks 

  • DovefromaboveDovefromabove Central Norfolk UKPosts: 64,642

    I don't like using cardboard or other sheet fabric as a mulch ... in my experience it provides the perfect conditions for slugs to lurk and breed over winter.  

    I'd rather weed the area, plant and  then mulch with wood chips or bark mulch.  

    “I am not lost, for I know where I am. But however, where I am may be lost.” Winnie the Pooh

  • ObelixxObelixx Vendée, Western FrancePosts: 22,270

    Cardboard is more usually used in vegetable plots where you weed after harvest and then put on a layer of cardboard covered with plenty of well-rotted manure or garden compost to hold it down.  This then all rots down over winter and is worked in by worms and other organisms to make the soil ready for cropping again in spring and thru the growing year.

    For ornamental beds it is more usual to apply the mulch without the layer of cardboard and after all the planting is done.  If your soil is in good fettle, you can then use a thick layer of chipped bark to stop light getting to the soil and allowing weed seeds to germinate and grow.   If your soil still needs improving, then the cardboard and mulch route is the way to go because the chipped bark will take a long time to rot down and will be a pain to remove for further soil conditioning and planting..

    "We don't stop playing because we grow old; we grow old because we stop playing." - George Bernard Shaw
  • IamweedyIamweedy Cheshire East. Posts: 1,364

    You could go round daily turning  the cardboard over and disposing of the slugs . I still remember collecting over 100 slugs I had despatched in about three days in 2016.  Yuck.  In the end I could even pick them off with garden gloves instead of a trowel . 


    'You must have some bread with it me duck!'

  • IamweedyIamweedy Cheshire East. Posts: 1,364

    If you try cardboard preferably the thinner stuff, you would have to plant through the cardboard, but even then bulbs might still not grow up straight.

    'You must have some bread with it me duck!'

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