Last week, I detailed the results of my first summer mulch experiment, noting that cardboard is a potential winner.  Meanwhile, Mom found a stash of huge boxes being thrown away and snagged them for my continuing mulch experiments.  I'm trying the cardboard out on some cucurbits and okra, as well as on two troublesome, weedy beds that need a kill mulch.  Sister cucurbit and okra beds are being left bare for comparison.

Despite the fact that I soak the cardboard well before using it as a mulch, I'm a bit concerned that it might be too slick for easy rain penetration.  I'll keep a close eye on the cardboard-mulched plants and perhaps add some organic matter on top of the cardboard or punch small holes in it to increase water penetration.  As Mark pointed out, if I can work the kinks out of cardboard mulch, there's a neverending supply in nearby towns and it's much easier to transport than other mulches.

In other mulch news, last year's newly transplanted comfrey patches are now big enough that I'm cutting them biweekly, adding the low C:N mulch to select garden beds.  So far, comfrey seems to be equivalent to grass clippings as a mulch --- providing fertilizing power, breaking down quickly, but letting some weeds through.  I have to mention that the bumblebees continued to feed from the cut flowers for over 24 hours after they were detached.  Another reason to plant comfrey in your yard...as if you don't have enough reason already!