If you are not growing anything special in your vegetable and flower beds, now is a good time to build up the soil health in anticipation of spring planting. Ground that is left bare is subject to soil erosion and you may lose organic matter that tends to be closer to the surface. Covering it with an organic mulch will soften the blows of raindrops and the mulch will slowly decompose and enrich the soil below. Fresh manure can be put on the surface and will work into the soil through rain and earthworms. Compost spread on top will also feed the soil and beneficial soil organisms. Cover crops like fava beans and vetch will protect the soil and add nitrogen, an essential nutrient for plants. And take care not to walk on wet soil so as not to compact it.
More Information: Soil Health