The most efficient way to reduce outdoor irrigation is pretty obvious — turn it off. But that, of course, is the least attractive option for most of us. Less drastic solutions are to irrigate less frequently and remove the thirstiest plants.

In other climate zones where humidity is high and rainfall frequent in summer, thirsty species thrive in home gardens. Here, they become water wasters.

Unless you have a naturally damp site, plants such as queen of the prairie (Filipendula rubra), hosta, exotic ginger (Asarum), cardinal flower (Ligularia cardinalis), most sunflowers (Helianthus), elephant's ear (Colocasia), and gunnera otherwise call for constant moisture from irrigation.

Rosemary McCreary, a Sonoma County gardener, gardening teacher and author, writes the monthly Homegrown column for The Press Democrat. Write to her at P.O. Box 910, Santa Rosa 95402.