Bringing Back the Natives Garden Tour Returns This Weekend
The 19th annual Bringing Back the Natives Garden Tour and Green Home Features Showcase returns to the East Bay online this weekend, April 15 to 16, and in person, May 6 to 7.
The online tour features Susan and Bill Teefy’s Castro Valley garden, according to tour coordinator Kathy Kramer. The in-person tour visits eight homes and gardens, including one in San Leandro, five in Castro Valley, including the Teefy’s, and two more locations in Hayward.
The April 15 online event begins with a keynote presentation by best-selling author Dr. Doug Tallamy, a native plant advocate who teaches and carries out ecological research at the University of Delaware.
Both tours encourage people to help local ecosystems by planting plants already well-adapted to local conditions and using fewer introduced species that lack those ecological advantages, Kramer said. They also showcase some homes’ green features, such as solar panels, heat pumps, and induction ranges.
Registration for both tours is at www.bringingbackthenatives.net.
While introduced species are often quite beautiful, native plants don’t need chemical aids or extra water in most years to grow, said Kramer. They have adapted over millennia to the local environment, while introduced species have not had time to.
Kramer said another big advantage is due to bugs — specifically the kind that feeds birds.
People know that birds eat seeds and nuts, but they require more protein when they reproduce, and caterpillars are a key food at those times, she said.
Even the smallest birds eat caterpillars themselves while feeding enormous numbers to their chicks, she said. After getting their protein needs met, they happily eat nuts and seeds, too.
Many homeowners go to a lot of trouble to kill pests but end up killing all insects, she noted.
“There are supposed to be insects to eat the plants, to feed the birds,” Kramer said. She added that most insects will not eat enough to kill the plant.
“Native plants are bird feeders,” said Tallamy. He noted that the U.S. and Canada have lost about 3 billion birds since 1970, partly because they keep encountering ecological dead zones where they cannot find enough food.
Tallamy said in a video posted on the Native Gardens website that it takes nearly 10,000 caterpillars total for chickadees, a relatively small bird, to raise a brood of chicks. Both parents take turns gathering food and deliver caterpillars about every three minutes to the nest, where the young stay for 16 to 18 days, his research shows.
Tallamy said that plants do their best to kill or discourage insects from eating them, so moths and butterflies have evolved defenses against specific plants’ poisons over thousands of years. They tend to specialize, laying their eggs that turn into caterpillars on one particular species of plant.
Monarch butterflies are famously dependent on milkweed, a plant that poisons almost every other species of butterfly or moth, he said. It took thousands of years of co-evolution for this to come about, he added.
Introduced species may look great but don’t feed the local insects and birds, Tallamy said.
Birds need about 70 percent of the landscape to be native for them to easily find enough food for their young, he added.
Both Kramer and Tallamy said that some plants were superb at providing habitat for other wildlife.
“Some 5 percent of our native plants make 75 percent of the foods that drive the food web,” Tallamy said. “Those are our keystone species.”
He added that while oaks and native cherries support many species of insects, introduced species like gingko support almost none.
“Oaks are the powerhouse of plants,” Kramer said. “Over 300 species of butterflies and moths can lay their eggs in them.”
Other keystone species in the Bay Area include native cherries, lupines, California lilacs, manzanitas, aster, and goldenrod, she said.
Kramer’s advice to local gardeners is to plant keystone species, to replace introduced species that bring you no particular delight, and not to mow your lawn so often nor sweep up leaves so fast. There may be moth or butterfly pupa in them.
Kramer also cautions that one might not be doing the environment a big favor by buying just any “drought-resistant” plant for our drought-prone climate.
“Drought-resistant’ often means a plant that evolved in a Mediterranean or southern African environment,” she said. “Look for a native plant with similar qualities.”
Many resources about native plant gardens are available on the Natives Garden Tour website at
www.bringingbackthenatives.net, including a section with talks and writings by Dr. Tallamy. Included there is a guide to which native plants grow easily in the Bay Area, broken down by garden conditions.
“Every square inch of the planet has ecological significance, including your yard,” said Tallamy.