Energy Adviser: Native plants cut down on watering costs



With average rainfall of more than 40 inches a year, you would think Clark County homeowners should have few worries when it comes to keeping yards happy. But water demand soars during summer months when temperatures climb, the ground dries out and delicate plants begin to fry.

Clark Public Utilities provides water services to 30,000 customers. Using drought-resistant native plants allows homeowners to have a beautiful yard while using far less water from the outdoor faucet.

Barbara Samuels, a Vancouver gardener who has participated in the Naturally Beautiful Backyard program, said homeowners can enjoy midsummer gardening without spending a fortune on plants or on water, by choosing wisely.

“When people look at my yard, they comment that it must be a lot of work,” Samuels said. “But what I do is really low maintenance.”

Native plants, say gardeners such as Samuels, are adapted to the Northwest’s climate of wet winters and dry summers. They require less water once established and are resistant to native pests and diseases, notes the Washington Native Plant Society at Native plants improve water quality by needing less fertilizer and no pesticides.

According to Kathleen Robson of Woodland, author of “Encyclopedia of Northwest Native Plants,” gardeners should be aware of a harsh, dry period that typically hits Southwest Washington during August and early September.

“We don’t get those thunderstorms that other places have in summer,” Robson said. “The good news is there are a lot of native, drought-tolerant plants from which to choose.”

She offers these buying tips:

• Take time to visit nurseries and see growing plants first-hand. Read labels for where they work best. Do research at

• Visit display gardens in the Vancouver-Portland area.

• Ask these questions before making a purchase: How big will this plant get? When does it bloom? Does it like shade or sun?

A common mistake, Robson said, is to put a drought-tolerant plant in a “rain garden” area, only to see it die when its roots sit in water during winter months.

Other gardening tips from the society:

• Plant drought-tolerant plants away from lawns or gardens that will be regularly watered, or plant them higher on slopes to minimize overwatering.

• Plant in the fall and early spring in order to give plants a chance to develop healthy roots before the dry season.

• Use layered plantings. Shade from trees will help understory plants thrive, and tall grasses or shrubs will help shelter more tender herbaceous plants from exposure to wind and sun.

• Consider replacing part or all of your lawn with drought-tolerant native shrubs, ground covers or stones and pebbles.

• Cover all exposed soil with dense plantings and mulch. The mulch will slow down evaporation and will keep the soil cool and moist.

• Control weeds, especially in the summer. They take water from garden plants.

• Water at dusk and dawn or use drip irrigation. Water deeply and infrequently. Soak the roots and then wait until the top few inches dry out before watering again.

Recommended books

These books can help as you seek to minimize water use:

• “Encyclopedia of Northwest Native Plants,” by Kathleen Robson. A comprehensive reference describes plants native to the Pacific Northwest. Illustrated throughout with 600 color photos.

• “Gardening with Native Plants of the Pacific Northwest: An Illustrated Guide,” by Arthur Kruckeberg. A primary resource on using Northwest natives in the garden.

• “Landscape Design for Wildlife,” from the Washington Department of Wildlife.

The Energy Adviser is written by Clark Public Utilities energy counselors, who provide conservation and energy use information to utility customers. Send questions to or to Energy Adviser, in care of Clark Public Utilities, P.O. Box 8900, Vancouver, WA, 98668. Past topics are available at