Don't count on fall and winter rains to provide water to all plants in the home landscape, said Jan McNeilan, Oregon State University Extension Service consumer horticulture agent.
Many plants grow in areas protected from the rains.
Plants underneath the wide eaves on many Oregon homes, for instance, are likely to be quite dry. Although most landscape plants are dormant in the winter, they still use some water. And with cold winter months coming up, a well-watered plant has greater protection against freezing than a dry one.