Plant your feet Sunday at the San Luis Obispo Botanical Garden

On a sunny September afternoon, the San Luis Obispo Botanical Garden hums with life.

Honeybees buzz in banks of purple-blossomed rosemary. Cabbage butterflies flutter past San Clemente Island mallow and Coast Live Oaks. A tiny brown lizard suns himself, sheltered by the spreading branches of a California buckeye.

Soon, supporters hope, the garden will be buzzing with human visitors as well.

The San Luis Obispo Botanical Garden celebrates its 20th anniversary Sunday with “Connections with Nature.”

The daylong event at the garden, in El Chorro Regional Park off Highway 1, features live music, children’s activities and more.

“One of the major goals of the garden is to get people more interested in nature,” explained Liz Scott-Graham, the botanical garden’s executive director.

“Everything in nature is fascinating if you explain it in the right way,” she said. “This garden will do that and use art and humor and technology … to do it.”

Sunday’s celebration has two purposes, organizers said: to recognize the garden’s past and share its future. As many as 600 people are expected to attend.

Visitors can attend lectures, tour the Preview Garden, hike up to Eagle Rock, and groove to music by the Cuesta Ridge Mountain Boys, Zongo All-Stars and others.

Event-goers are also invited to attend “A Thousand Small Steps to Becoming Green,” featuring 40 “sustainable living” exhibitors and authors. Local vendors include the Brown Butter Cookie Co. in Cayucos, Green Goods in San Luis Obispo and Madrone Landscapes in Atascadero.

Children, meanwhile, can paint pots, plant succulents and participate in a scavenger hunt at the new Children’s Edible Garden.

“Connections with Nature” pays tribute to the garden’s founders with a special ceremony and dinner.

The garden’s history

According to founding member and garden manager Eve Vigil, the seeds of the San Luis Obispo Botanical Garden were planted in 1989.

While studying ornamental horticulture at Cal Poly, Vigil got a summer landscaping job with Los Padres National Forest. “They wanted beautiful drought-tolerant plants,” she recalled.

When Vigil couldn’t find anything in local nurseries, she traveled to California’s many botanical gardens for inspiration.

“I said, ‘How come we don’t have a botanical garden in this county?’ ” Vigil said. “Simply nobody had pushed a project like that.”

Friends of the San Luis Obispo Botanical Garden incorporated as a nonprofit organization in 1991.“Quickly we realized that the most important thing was land,” Vigil said.

The group settled on a portion of El Chorro Regional Park and, in 1993, signed a 40-year lease with the county Board of Supervisors.

A onetime pasture for local ranchers and dairy farmers, the 150-acre parcel served as U.S. Army training grounds during World War II and the Korean War. One fenced-off area featured a sign that read “No Trespassing — Explosives,” indicating its use as a grenade range.

Several factors made the site ideal for a botanical garden, Vigil said.

For starters, grazing cattle had all but eliminated native vegetation, meaning that the garden’s founders could work without destroying delicate ecosystems.

“To have a site that was basically a blank palette was very important for us,” she said, adding that the group was also attracted by the land’s proximity to a major highway.

Two decades of growth

Over the past 20 years, the San Luis Obispo Botanical Garden has begun to realize its potential.

A one-acre Preview Garden opened in 1997, followed by a greenhouse and nursery a year later.

The Oak Glen Pavilion, which opened in November 2007, features a straw-bale education center and catering kitchen as well as a garden shop, offices and library. The grounds include the Life Celebration Garden and an open-air amphitheater.

Up to 60,000 people visit the San Luis Obispo Botanical Garden each year, Scott-Graham estimated, adding that it has 850 members and 256 active volunteers.

That annual visitors tally could swell to 750,000 when the garden is complete.

Not finished yet

Still, supporters said, much remains to be done.

They’re currently amending the garden’s award-winning master plan, completed in 1998, to meet projected needs.

The completed garden, estimated to cost $40 million, will feature five “signature landscapes” that showcase the world’s Mediterranean climate zones: California, the Mediterranean basin, Chile, South Africa and Southwestern Australia.

Each region features plants that thrive during warm, dry summers and mild winters.

Scott-Graham envisions a future in which all plants in the garden come equipped with radio-frequency identification tags and GPS markers. Visitors would be able to learn about a particular plant — its size, lifespan and cultivation requirements — with a wave of a smartphone.

Other amenities under consideration include a 5,000-seat amphitheater, a gondola-style transportation system and several eateries specializing in locally grown food.

Right now, the focus is on fundraising, planning and permits.

According to board president Dave Porter, the garden is looking to the Monterey Bay Aquarium and the Eden Project in Cornwall, England, for inspiration.

“If you want to accomplish something that’s world-class, you have to aim high,” Porter said.