From a 2009 article by Gregg Lowery of Vintage Gardens:
"We are indebted to a scientific study done at the University of California at Berkeley in recent years. It showed that while green leaves can harbor fungal spores, once the leaves die, the fungi die on them. This leaves us with a simple cleanup process, and one that obeys the basic rules of recycling in the plant world. All leaves when dead decompose and add to the soil the nutrients that were stored in them. They become compost. If we want to avoid the possibility that some of those leaves will stay green and keep fungi alive, we need only cover the leaf litter on the ground with a light covering of decomposed organic matter—mulch. They will then die completely and become an additive to the soil to enrich it."
