December is the perfect time for to plant pansies. They work especially well when mixed with bulbs. It is an excellent time for planting trees and shrubs. Take care to not plant them too deep and water them carefully, not letting them dry out or become too wet. For successful planting, always pick a species that is well adapted to our zone.
http://planthardiness.ars.usda.gov/PHZMWeb/Default.aspx
If you are in the planning stages to create a new shrub, flower or rose bed for spring now is the time to prepare the soil. Remove any weeds and work in compost (leaves will also work) and expanded shale into the bed. Do not leave the soil bare. My favorite alternative to a cover crop is to spread a thin layer of dried molasses over the bed. Cover it with about two sheets of newspaper and topped off with an inch or so of mulch. When the time comes to plant just turn it all into the soil.
