Earthworms, and other members of the Soil Food Web, like the soil conditions created when mulches are used, cool, moist soil, so any material used as a mulch will get them there. Shredded cardboard will work, but I am not sure that the extra labor involved in shredding cardboard is really worth the effort. I see very little difference in my soil if the cardboard is laid down unshredded or if I shred it, except I need more shredded cardboard to get the same results as with unshredded cardboard, and the shredded cardboard allows more "weed" growth then the unshredded cardboard does.

I got a paper shredder that eats cardboard so long as it isn't too thick. My old paper shredder did eat cardboard for a little while but then I think we fed it too much and it broke. The fellows power shred seems to do pretty well with cardboard. I got one that doesn't take that many sheets of paper at once but it is rated to run alot and still seems to take most corrigated cardboard. This is all if you really need shredded cardboard. I like to use large sheets of cardboard as the bottom layer for new lasagna beds. I only shred cardboard for use as cover materials in compost buckets or for new bedding in the worm bin. The worms don't really need it shredded as they are quite happy with layers of big cardboard over top of their bedding. A bit of moisture and the cardboard tends to fall apart. I've also found that simply dipping cardboard into a bin or bucket of water will make pealing off tape quite easy and leaving the box in the water for more than a moment will allow it to fall apart really easily.

Yea it's totally stupid to throw good food away, and even worse throw good compostable food and cardboard to the dump when it could be the food for worms which supplies the castings to fertilize food for people. Will Allen, founder of Growing Power uses just such a method to make compost with worms, that he feeds to fish that he grows in Greenhouses with plants fish and worms in an integrated growing system in downtown Milwaukee and Chicago. He produces tons and tons of food with urban trash, worms and hard work. Know anybody at Publix I can talk to to enlighten them? Ren Here is a link that might be useful: Growing Power Vermicomposting

I use Shredded Corrugated Cardboard exclusively as bedding. I have a 12-sheet, strip-cut shredder for cardboard. A machine lasts me about 3 years. I'm on my 3rd shredder. If cardboard is too thick to go through the feed slot, then just separate the layers until it fits. I always look for clean cardboard to shred, without colored printing. For shredding small stuff, the bin that comes with the shredder is enough,. But for our purposes, it's not. I store shredded cardboard in XXXXL size, heavy-duty, garden waste plastic bags. Find a large, heavy-duty cardboard box about the size of the bag you're going to store the stuff in. Fold the flaps closed on one end and place that end on the floor. Now you have a collapsible frame to hold your collection bag. Place the bag inside and fold some of the open end over the top. Now you need something to hold the shredder head. A simple rectangular-shaped holder can be made from scrap wood or angle iron, or aluminum. Two long pieces, long enough to fit across and rest upon the cardboard box and two shorter pieces, connecting them. The shredder head fits on top. The opening only has to be big enough for the exit slot of the shredder. The shredded cardboard/paper goes straight into the collection bag. When you're done, remove the head and holder, and then pick up the cardboard box that's holding the collection bag. The flaps on the bottom should open by themselves (since the flaps weren't sealed shut). This way, there's no need to have to pick up the bag (which will probably be heavy). Then just store the cardboard box flat, along with the shredder-head holder and that's it.