Today's garden plants can be tomorrow's invasives

  • An overlook at Point Mugu State Park, where fountain grass, with its showy red heads, is pushing out the native plants.

    Lynn Sweet, Cal-IPC
  • Giant reed arundo outcompetes native species with its rapid growth and high water uptake

    John M Randall, The Nature Conservancy, Bugwood.org
 

On a misty summer morning, ecologist Christy Brigham sinks down to the sand at Point Mugu State Park, part of the patchwork of federal, state and private lands in Los Angeles County's Santa Monica Mountains. She watches a darkling beetle forage among rare dune plants -- lacy, lavender sand verbenas and beach primroses, which resemble large buttercups. When Brigham came to this area eight years ago to work for the National Park Service, she thought she'd become an expert on plants like these, part of the region's unique Mediterranean-climate flora. But instead, she's spent most of her time dealing with common plants, many of them fugitives from local gardens and nurseries. She points out a thicket of fountain grass (Pennisetum setaceum) nodding its blond, tufted seed-heads in the breeze. It's already overtaken some of the dune plants and is closing in on more. Fountain grass, an invasive from North Africa that became popular in California gardens in the 1990s, is "very drought-tolerant and can grow in a lot of different habitats," Brigham explains. "I've seen it expand massively. It's just everywhere."

Indeed, in recent years, fountain grass has elbowed its way onto thousands of acres in Southern California, cropping up in a startling array of places -- along the coast and in the deserts, on hillsides, in streambeds, on rocky slopes -- even in cracks in urban alleys. Brigham notes that in infested areas, "we have found few native plants, fewer animals." The plant is also highly flammable. And fountain grass has plenty of company: The nonprofit California Invasive Plant Council has identified some 100 ornamental plants, introduced through gardens or deliberately planted for erosion control, running amok in California alone. There are forests of non-native tree-of-heaven, thickets of castorbean and Spanish broom, groves of Mexican fan palms and thousands of acres of bamboo-like arundo.

In addition to creating dense monocultures, some invasive plants slurp up precious river water, cover the gravel beds fish need for spawning, and push already-rare species to the brink of extinction. Yet despite the region's long experience in waging an expensive and Sisyphean battle against the likes of tamarisk, arundo and other big, bad weeds, many nurseries still sell known runaways, in part because of lax regulations and limited government resources. And it's hard to convince state agencies and the industry that a pretty garden plant is a problem. "It has to get where it's hurting people somehow -- visibly ecologically, economically, or causing fires -- to get the public's attention," says Ed Northam, a weed biologist with the University of Arizona Cooperative Extension. "But when you're at that point, it's a little late."

Western states have been at war with weeds for more than a century. State weed programs, however, tend to focus on plants that hamper agriculture and ranching. Rogue garden plants, typically perennials that farmers can easily vanquish through tilling, primarily threaten wildlands -- less-familiar ground for state ag agencies. And many states are reluctant to impinge on their horticultural industries. When California's Department of Food and Agriculture banned the sale of a handful of the state's worst invasive plants a few years ago, it declined to include invasive pampas grass, which plays a considerable part in the state's $2.7 billion wholesale growing industry. Instead, it prohibited jubata grass, a pampas relative that's seldom sold or grown in the state. "CDFA's argument was that there was going to be a lot of resistance," says Joseph DiTomaso, co-author of Weeds of California and Other Western States. "So they went with all the easy ones." The agency responds that state agriculture code prevents it from banning a wildland weed if doing so is "detrimental to agriculture." The detriment in this case, according to spokesman Steve Lyle, was economic loss to the cut-flower industry, which grows pampas plumes.

Oregon has shown more moxie. The state banned the sale of butterfly bush (Buddleja davidii) in 2004 because it invades logged forests, pastureland and riverbanks. Last year, it prohibited the sale of all plants commonly sold as English ivy (Hedera helix, Hedera hibernica). Ivy now smothers the ground throughout the greater Portland area, impeding the growth of native sword ferns and wildflowers such as snowberry and weighing down the trees it climbs, making them more likely to topple in storms. Quashing an ivy infestation and restoring native plants costs as much as $10,000 an acre, says Jonathan Soll, stewardship manager with Metro, a tri-county governmental agency that manages parkland. Even so, it took nearly two decades of surveys and advocacy to get the ivies pulled from nursery shelves. "We had to document that it wasn't just a city phenomenon," he says. "We had to show it was moving and was going to keep moving until it wreaked havoc throughout forests in Oregon."

High Country News Classifieds
  • ADOBE HOME
    Passive solar adobe home in high desert of central New Mexico. Located on a 10,000 acre cattle ranch.
  • EXECUTIVE DIRECTOR
    Western Slope Conservation Center Paonia, CO WSCC seeks a dynamic leader who is mission-driven, hardworking and a creative problem-solver. Position Summary: The Executive Director leads...
  • ARIZONA STATE DIRECTOR
    A LITTLE ABOUT US Founded in 1951, the Nature Conservancy is a global conservation organization dedicated to conserving the lands and waters on which all...
  • CONSERVATION MANAGEMENT/HOSPITALITY SERVICES
    Seasoned ranch manager of award-winning conservation ranch seeking position as nature reserve/resort or ranch manager. Visit philipmoonwalker.com for resume and certifications. Contact: [email protected]
  • PART-TIME OREGON GRANT WRITER
    Help advance rights for people, communities, and nature - Part-time grant writer. The Oregon Community Rights Network (ORCRN) has been active over the last six...
  • UTAH PUBLIC LANDS PROGRAM DIRECTOR
    Job Title: Utah Public Lands Program Director Location: Southern Utah Position: Full Time (40 hours per week) Supervisor: Conservation Director About us: The Grand Canyon...
  • FSBO PROPERTY-SOUTHEAST ARIZONA
    Located in an area steeped in history, this gentleman's ranch sits at the entrance to the renowned Cave Creek Canyon. Enjoy picturesque views of the...
  • EXECUTIVE DIRECTOR
    Eastern Nevada Landscape Coalition, based in Ely, Nevada is looking for a new executive director to replace the long-time executive director who is retiring at...
  • LAND CONSERVATION PROJECT MANAGER
    JOIN OUR TEAM! The New Mexico Land Conservancy in Santa Fe is seeking a Land Conservation Project Manager who will work to protect land and...
  • HOME NEAR CAPITOL REEF NP
    Comfortable home at foot of Boulder Mountain, on one fenced acre. Amazing views!
  • STEVE HARRIS, EXPERIENCED PUBLIC LANDS/ENVIRONMENTAL ATTORNEY
    Comment Letters - Admin Appeals - Federal & State Litigation - FOIA -
  • LISA MACKEY PHOTOGRAPHY
    Fine Art Gicle Printing. Photo papers, fine art papers, canvas. Widths up to 44". Art printing by an artist.
  • LOG HOME IN THE GILA WILDERNESS
    Beautiful hand built log home in the heart of the Gila Wilderness on five acres. Please email for PDF of pictures and a full description.
  • NEW MEXICO PROPERTY - SILVER CITY
    20 acres, $80,000. Owner financing, well, driveway, fencing possible, very private, sensible covenants, broker owned. Contact - 575-534-7955 or [email protected]
  • SECLUDED COLORADO HIDEAWAY
    This passive solar home sits on 2 lots and offers an abundance of privacy and views while being only 15 minutes to downtown Buena Vista....
  • CARETAKER
    2.0 acre homestead needing year-round caretaker in NE Oregon. Contact [email protected] for details.
  • SEEKING PROPERTY FOR BISON HERD
    Seeking additional properties for a herd of 1,000 AUM minimum. Interested in partnering with landowners looking to engage in commercial and/or conservation bison ranching. Location...
  • COPPER STAIN: ASARCO'S LEGACY IN EL PASO
    Tales from scores of ex-employees unearth the human costs of an economy that runs on copper.
  • EXPERT LAND STEWART
    Available for site conservator, property manager. View resume at http://skills.ojadigital.net.
  • CONSERVATIONIST? IRRIGABLE LAND?
    Stellar seed-saving NGO is available to serious partner. Package must include financial support. Details: http://seeds.ojaidigital.net.