The problem with composting paper & cardboard

[Nikki]

I recently read that paper and cardboard contains soy or soy inks, so it's best not to compost them. Is this only an issue if you're allergic to soy?

edited to add:
I should have added that I garden exclusively organically. So I was wondering if it's an organic issue as well.

[Rod in Japan]

I think your informant may have got that a little muddled up.

All ink including soy ink contains waxes, pigments and other materials including toxic heavy metals. If you were to compost materials with ink on them, those substances would end up in the soil. So it's not the soy aspect that you need to worry about - it's the other things.

Also, I found that cardboard and newspaper tend to form solid clumps in compost and make it heavy and unpleasant. (I stopped trying to compost it after I found out about the heavy metals.)

[prison break fan]

Rod in Japan, you've really depressed me! I have just covered half my allotment with a layer of cardboard, then a layer of horse manure and then a layer of hay and grass cuttings! pbf

[Rod in Japan]

pbf, I don't think you need to be depressed about it. The amount of ink on the cardboard is probably not that much, and the amount of dodgy substances in the ink is also probably not that much, and how it affects soil and plants is also probably not much.

I think it's probably just something to be aware of if you're an absolute purist. I avoid paper because it doesn't rot down particularly gracefully and it looks just like rubbish strewn about.

[prison break fan]

Rod in Japan, I hope you are not just trying to cheer me up! I used masses of newspaper on the soil last autumn and found it just didn't rot down, but the cardboard vanished beautifully. I think it is like most things in life, you just have to do your best with what you've got!! pbf

[Flo]

A little newspaper shredded or crumpled and mixed in well will rot down well enough in a compost heap that gets hot enough. It doesn't work in layers like cardboard. It's on the Garden Organic list of things you can use with the note that it's actually environmentally better to send it for recycling. They pretty much describe the way I was shown as a child and the way I've always composted that has given me good results. So I'll go with their advice.

[ina]

I only use the brown cardboard boxes (and stuff like toilet rolls) in the garden - seem to have no problems with that, i.e. can't find them again a year after... And I don't think there's much ink on them, either.

[wulf]

I line my kitchen compost bin with a single sheet of newspaper. This prevents the inside of the bin getting covered with rotting clumps. The whole lot goes in the compost bin outside and rots down very well - I don't find that I'm reading old headlines by the time the compost is ready.

Wulf

[Rod in Japan]

Wulf, that's what I used to do too, hence my experience with newspaper in compost. I was using one of those plastic composting Darleks and I'd end up with a tightly packed wodge of kitchen waste packages and soggy newspapers.

I suppose if you have a more open compost arrangement and fork it periodically, the paper would indeed compost nicely. It's really hard to get a fork into a Darlek - it keeps zapping at you with its toilet plunger.

[ina]

One market garden I worked for, we used loads of newspaper, thickly folded, around all veg beds as slugs traps. (Slugs shelter under the damp newspaper, and you just need to take them up once in a while an collect the beasties.) As long as the papers were kept damp (rarely a problem in Scotland!), they simply disappeared over the year. Earth worms seemed to like them, too.

[Nikki]

So useful to know! I'm a compost virgin.

Might it be successful and beneficial to compost paper separately? It's that recycling initiatives where I live are facades.

[ina]

You'd be better off with a mix of stuff. Just don't put too much paper or cardboard in at once; scrunch it up a bit so that there's air in it as well, and keep it moist.

[Rod in Japan]

Might it be successful and beneficial to compost paper separately? It's that recycling initiatives where I live are facades.

If you really want to compost paper on its own, you might want to try a wormery. If you were to place some sort of covered box on bare soil, follow ina's advice for the paper, and maybe drop in some red worms, you might be able to get a soil-making thing going. I have read that worms will actually make compost out of paper alone. Unless you actually started off with a lot of worms though, it would take a long time before they started to digest large quantities of paper.

[Peggy Sue]

I was under the impression its the coloured inks that were really a toxic problem, B&W wasn't really an issue (hence most newspaper& cardboard were OK)?

[Annpan]

I have never thought twice about it... just chuck it all in Though most paper does get burned instead - then the resulting ash goes on the compost heap.

But TBH how many chemicals do you inhale when walking down a busy street, how many chemicals leach into meat and veg that has been wrapped in plastic and how many chemicals are released into the air by transporting and recycling rather than composting said paper and cardboard... sometimes I think we are best not to worry so much.