nickolas
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Posts: 161
Joined: Sat Jul 23, 2011 7:04 am
Location: Victoria, Australia

Shredded cardboard as mulch.

Hey guys. I started using shredded cardboard in my garden a few months back. I can get a 6ft L x 4ft W x 6ft H trailer load of cardboard boxes from the local supermarket across the road from where I work once a week for free. I started running the mower over it to shred it up. Now I add it to the compost, worm farm, as mulch for veggies and mix it in when I make soil. I was wondering if it might rob nitrogen from the soil when it brakes down? I have really bad soil here (solid clay) so I have to make all my soil from scratch. I have mulched a number of beds with it and so far I have started to notice as the temperature is warming up that it seems to be holding moisture in the soil, particularly up near the surface. I know most mulch will do this but one of the problems I have had with the mulches I have tried so far is weed seeds. Of course this has none. It seems to be doing a reasonable job of reducing weeds from coming up as well considering I'm not applying it very thick (about 1-2”). the worms seem to be loving it as well which is a plus.

Anyone else using it like this? Or have any other uses for cardboard? As its starting to pile up xD

imafan26
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Joined: Tue Jan 01, 2013 8:32 am
Location: Hawaii, zone 12a 587 ft elev.

I've used it as weed control, it works pretty good. After a while all the pill bugs, beetles and worms start eating the cardboard.

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applestar
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Joined: Thu May 01, 2008 7:21 pm
Location: Zone 6, NJ (3/M)4/E ~ 10/M(11/B)

As long as it is left on the surface as mulch and not worked in until the cardboard is completely broken down into compost, I don't think nitrogen deficit will be a problem. The earthworms absolutely LOVE moist cardboard. I think you'll get good activity and increased worm population.

As things worm up, you could also layer grass clippings and wilted pulled/hoed weed for additional greens to add more nitrogen. Mixing this into the cardboard will of course make compost faster. Worms will leave if it get too hot but will stay in the periphery and work where they can.

Finished compost can be worked into the soil.

...since you work at the supermarket, it might be easy matter to also get spoiled/scrap veg and fruits (also "greens") to mix into your compost pile and balance the cardboard "browns".

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rainbowgardener
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Location: TN/GA 7b

Even as mulch, not just in the compost pile, I have been doing green + brown mulch for the past couple years - pile or layer on grass clippings, pulled weeds, etc with the browns (which in my case are mostly fall leaves). It is easier for me to get a good thick layer of mulch that way AND it breaks down faster and I think makes a more complete food for the soil.



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