Fall is the ideal time of year to prepare your raised garden beds. Timing your preparation this way will give the organic matter you are incorporating ample time to break down into usable nutrients for your garden. By the time planting season rolls around, your raised garden beds will have virtually done all the preparation themselves. Careful layering of organic components for breakdown, combined with a cover against the harsh winter elements will take only a little thought and preparation.
Mark the area where you will be preparing your raised bed. Use stakes and string or untreated wood planks for this purpose.
Soak a large quantity of shredded newspaper thoroughly with your garden hose. Apply a thick layer to the bottom of your raised bed. It will attract earthworms, which aid greatly in all types of garden preparation.
Alternate layers of compost, shredding, grass clippings, leaves and soil on top of the newspaper. Use your shovel to spread these layers out evenly.
Cover the raised bed with black plastic when you are done. Use bricks or heavy planters to hold the edges down so that it does not blow away. This layer of plastic will heat the bed, encouraging decomposition. It will also protect vital nutrients from washing away over the winter.