Organic Gardener's Composting by Steve Solomon

Yes, gardening under permanent year-round mulch seems easy, but it does have a few glitches. Ruth Stout did not discover them because she lived in Connecticut where the soil freezes solid every winter and stays frozen for long enough to set back population levels of certain soil animals. In the North, earwigs and sow bugs (pill bugs) are frequently found in mulched gardens but they do not become a serious pest. Slugs are infrequent and snails don't exist. All thanks to winter.

Try permanent mulch in the deep South, or California where I was first disappointed with mulching, or the Maritime northwest where I now live, and a catastrophe develops. During the first year these soil animals are present but cause no problem. But after the first mild winter with no population setback, they become a plague. Slugs (and in California, snails) will be found everywhere, devastating seedlings. Earwigs and sow bugs, that previously only were seen eating only decaying mulch, begin to attack plants. It soon becomes impossible to get a stand of seedlings established. The situation can be rapidly cured by raking up all the mulch, carting it away from the garden, and composting it. I know this to be the truth because I've had to do just that both in California where as a novice gardener I had my first mulch catastrophes, and then when I moved to Oregon, I gave mulching another trial with similar sad results.