Marin Headlands Native Plant Nursery
Re-Seeding Coastline: There is no quick, mechanized way to restore native vegetation to woodlands and parks that have been invaded by exotic plants. It takes time, people, funds, planning and work before Mother Nature can take over and finish the job. In the Golden Gate National Recreation Area
, the world's largest urban park, it takes a lot of the above. One way that you can help is explained in the last paragraph, but first is an explanation of the restoration process currently underway in the GGNRA.
The task of restoring native flora to the GGNRA's 75,000 acres falls on the Golden Gate National Parks Association, a non-profit organization that supports the National Park Service in managing the GGNRA, which includes, among other areas, the Presidio, Alcatraz, Fort Point, Land's End and, closer to home, Muir Woods, Tennessee Valley, the Marin Headlands and part of Mt Tamalpais. The removal of invasive non-native plants such as french and scotch broom, cape ivy, cotoneaster, iceplant and pampas grass is only part of the job, and the GGNPA has five native plant nurseries, located in Muir Woods, the Presidio, Fort Funston, Tennessee Valley and the Marin Headlands, that handle stage two: the restoration of native vegetation.
The newest of these nurseries, the five-year-old Marin Headlands Native Plant Nursery, with a paid staff of one, is in the process of restoring native plants to the southern edge of Marin County. The staffer, Nursery Manager Erin Heimbinder, is fortunately not alone in this task. Interns are involved in nearly every aspect of the management of the nursery and its public programs, and about 700 volunteers each year assist in the multi-step process that makes up the native plant propagation effort.
The successful growing of a native plant is more than just a "dig hole, drop seed, fill hole" kind of process, and different plants require different preparatory tasks, growing conditions and care. The nursery recently completed the planting of the native "silvery lupine", or Lupinus albifrons, and Heimbinder used this plant to explain one such process to us. "We collect Lupinus albifrons
seeds in their pea pods from existing plants on GGNRA land during the late spring and early summer," she explained. "Following collection, we remove the seeds from the pods by hand at the nursery."
No, don't dig that hole yet. Before the seeds can be sown, they are placed in a rock tumbler for two hours, a device that scarifies, or scratches, the shiny, impermeable seed coating so it can absorb water and begin the germination process. After scarification, the seeds are soaked for three hours in fresh water, and those that sink have absorbed enough water to be candidates for planting. As is often the case in life, there are always a few bad seeds, and those that fail the absorption test the first time around are dried out and returned to the rock tumbler for another try.
Now you can dig the hole, but in a container, not in the ground. The maturing plants are grown in containers for about eight months. The containers are kept in a "shadehouse," an enclosed netted structure that filters some of the sun so the plants do not burn. During the eight months, the lupines are watered and inspected for diseases and insects, and treated organically if any are found. Heimbinder recalled, "We had a problem with thrips during the winter evidenced by discoloration in the leaves. We treated the plants with a soap water solution called Safer's Soap to eliminate the pests."
A final location for the plants must be determined, and Heimbinder described the environment that the silvery lupine (photo below right) prefers. "Lupinus albifrons thrives in areas where there is little to no overstory; they do not fair well in the shade," she noted. They were planted near Hawk Hill and Battery 129 in the Headlands, an area that is being restored to a coastal grassland.
When you consider that this is the procedure for restoring just one species of plant, and that the nursery is attempting to propagate many other native plants, including the Coast Live Oak, California Sage, Bay Laurel, Wallflower, Coyote Brush and Honeysuckle, the task takes on mammoth proportions. Why do it then? Heimbinder had a few reasons, the most obvious being, "...to recover endangered species, both plants and animals." The effort that Heimbinder related about growing the silvery lupine has more impact than just restoring those plants, a worthy goal in itself. "The silvery lupine is the host plant for the federally endangered Mission Blue butterfly," she said. "Without this plant the butterfly would completely disappear."
Heimbinder listed other reasons: "Revegetating prevents future invasions by exotics, restores natural areas that have been degraded by off-trail trampling, erosion or old infrastructure, and maintains biodiversity in areas that have been impacted by exotic invasions."
When asked how the silvery lupine that were planted near Hawk Hill are doing, Heimbinder reported with the muted optimism of a concise field worker, "Qualitative observations of the planting site indicate they are doing very well. Formal monitoring next spring will provide more precise information." Things do not always go this smoothly however. "One morning, I provided a tour of the nursery to a group of people, and showed them around a shadehouse," she related. "Later that afternoon, I realized that we had some unwelcome visitors in the shadehouse." The door had been accidentally left ajar, and a family of deer, who as far as they were concerned came upon a heaven-made all-you-can-eat salad bar, were sedulously munching on the maturing native plants.
Volunteers make a huge difference in the Golden Gate National Parks, and the native plant nurseries have collected millions of seeds and grown hundreds of thousands of plants with the help of the community. There are often opportunities to join in the native plant restoration process while enjoying the exercise and being in the outdoors. For information about how you can help, call 415-332-5193 or visit the Parks Conservency
website. The Mission Blue butterfly, and all life, will benefit from your help. Written by Alan Nayer. Text © Alan Nayer. The three accompanying photos in this article © Marin Headlands Native Plant Nursery. Used with permission.