Farmers sowed 'habitat plantings' one-meter wide the lengths of their fields. They used mat-forming perennial grasses and flowers and left the areas uncut for two years. Entomologists then sampled for insects. They found more than 100 times the populations of beneficials in the habitat strips than outside of them. These insects were also foraging ten meters into the fields to dine on pest insects. This study's most important message is to a border of perennial plants near your vegetable garden where beneficial insects can overwinter.

For plant lists and full details on gardening in December, order your copy of Seattle Tilth's Maritime Northwest Garden Guide, a planning calendar for year-round organic gardening.