It's getting harder and harder to find reasons not to garden with natives, those plants already adapted to local climates and soil.

On the practical side, savvy Bay Area gardeners recognize their ease of maintenance and lower water needs, while aesthetics proves their beauty, attraction to wildlife and a true sense of place.

Given these attributes, it should come as no surprise that the Bringing Back the Natives Garden Tour is celebrating its ninth year with 40 Alameda and Contra Costa County gardens primed and ready to strut their native-is-beautiful motto for all to see.

On May 5, registered participants for the free tour will be able to follow self-drive directions to gardens of their choosing; wander paths and identify their favorites; ask questions of owners, volunteers and designers, and stay for garden talks.

Bob Sorenson  next to a cows parsnip plant on a hillside behind his Orinda, Calif. home on Sunday, March 24, 2013. He restored the hill with native plants.
Bob Sorenson next to a cows parsnip plant on a hillside behind his Orinda, Calif. home on Sunday, March 24, 2013. He restored the hill with native plants. The hill had previously been stripped of vegetation by grazing cattle. Bob's home is on the Bringing Back the Natives Garden Tour. (Jim Stevens/Staff)

During the native plant sales Saturday and Sunday, May 4-5, in Concord, and Sunday, May 5, in Orinda and Walnut Creek, native plant nurseries will offer a broad selection of plants as well as personal advice.

Information gathered by organizer Kathy Kramer from previous years shows that people participate to become better informed and she notes that this is a good year for do-it-yourselfers, since the tour offers many homeowner-designed and installed gardens.

New this year are five select tours, created for those who want to explore a specific topic. They range from gardening with nature in Walnut Creek, to installing a drip irrigation system in Lafayette.

"You can learn to sheet mulch and remove your lawn in Lafayette and Concord," Kramer said. "On one tour people can visit three gardens in Berkeley, Albany and Richmond that were self-designed and installed."

There are 14 tour gardens in Central Contra Costa County, so preplanning is the way to go. Kramer urges early registration to ensure a spot and to receive the garden guide.

Next should be a visit to the "view the gardens" section on the tour website where descriptions, plant lists and photos assist with making choices. Kramer also recommends printing out plant lists for each selected garden.

"Plants in the gardens are labeled so this way people can mark on the list those plants they find appealing and are doing well," she said.

Roy and Rosadelia Detwiler's Concord garden features foliage, fountains, flagstones and ponds in garden areas designed to attract wildlife.

Fern, edible and succulent gardens attract butterflies while Pacific chorus frogs and birds visit the two ponds connected through a series of channels. Native favorites, including yarrow, manzanita, milkweed and buckwheat, share garden space with ceanothus, clarkia, monkey flower and coffeeberry.

Another attraction will be Peter's Plants, on site Sunday to sell a variety of California natives, fruit trees and shrubs.

In Martinez, Chris and Marianne Dundon's garden is a great example of a low-cost, low-maintenance, low water-use do-it-yourself project.

Chris Dundon sheet-mulched his front lawn and installed a drip irrigation system and plants -- all in one weekend -- and will describe the process in a garden talk.

Visitors can meander across basalt steppingstones through a combination of Douglas irises, grasses, coffeeberry, sages and California lilac watching birds and bumblebees attracted to this garden.

Nancy Wenninger wanted to attract birds to her Walnut Creek garden and has seen more than 90 species above or in her yard, attracted by differing plant heights, water features and a bounty of nectar, seed and fruit-bearing plants.

A sunny side patio teems with wildflowers while her steep back garden is lush with ferns, currants, coral bells and redwood sorrel. Wenninger will share her "gardening for the birds" knowledge with a garden talk.

Many gardeners are taking the native movement one step closer to home, planting local native plants. One example is the Orinda garden of Bob and Stephanie Sorenson, featuring around 150 species from local natives, many grown from seeds and cuttings Bob Sorenson collected.

The garden is a wildlife favorite with numerous birds, and newts breeding in the pond. Narrow trails crisscross backyard slopes planted with coyote bush, dogwood, sword fern and toyon, and two bridges span the creek.

A garden talk by designer David Bigham will focus on gardening with local native plants.

Even after nine years, Kramer's goals remain constant.

"I hope this tour encourages people to consider including native plants in their garden," she said. "They belong here in California and they provide a sense of what California is."

if you go
What: Bringing Back the Natives Garden Tour
When: 10 a.m.-5 p.m. Sunday, May 5
Where: 40 gardens in Contra Costa and Alameda counties that are pesticide-free, water- conserving, provide habitat for wildlife, and contain 60 percent or more native plants. Garden addresses mailed to registrants in April
Cost: Admission is free (donations accepted), but space is limited and registration is required; registration will close when tour reaches capacity, or April 27, whichever comes first
Registration and information: Visit www.bringingbackthenatives.net

MORE SATURDAY EVENTS
What: Native plant sales
When: 10 a.m.-5 p.m. Saturday, May 4
Where: Markham Nature Park and Arboretum, 1202 La Vista Ave., Concord

What: Garden talk
When: 11 a.m. and 2 p.m. Saturday, May 4, "Top 10 plants for a native plant garden" by Kelly Marshall of Kelly Marshall Garden Design
Where: Markham Nature Park and Arboretum, 1202 La Vista Ave., Concord

MORE SUNDAY EVENTS
What: Native plant sales
When: 10 a.m.-5 p.m. Sunday, May 5
Where: Markham Nature Park and Arboretum, 1202 La Vista Ave., Concord

What: Peter's Plants will be selling native plants, pomegranates, figs, raspberries, grapes and non-native succulents
When: 10 a.m.-5 p.m. Sunday, May 5
Where: Roy and Rosadelia Detwiler's garden, 1230 Krona Lane, Concord

What: Lost Valley Nursery will sell native plants
When: 10 a.m.-5 p.m. Sunday, May 5
Where: Elizabeth O'Shea and Richard Howard's garden, 51 Lost Valley Drive, Orinda

What: Central Coast Wilds will sell native plants
When: 10 a.m.-5 p.m. Sunday, May 5
Where: Home of Meg McShannic and Dave Wallace at 1070 Homestead Ave., Walnut Creek

SELECT TOURS
What: Exclusive, guided tours of inspirational native plant gardens
When: Earliest tour April 6; last tour May 19
Where: Gardens in Concord, Walnut Creek, Lafayette, Berkeley, Albany and Richmond
Cost: $30 per person/tour (no refunds or exchanges)
Tour details/Registration: www.bringingbackthenatives.net/select-tours