Saving the Bluffs
By Margaret Buranen
an excerpt from Hydroseeding Challenges for all
Published in the Nov/Dec 2013 issue of Erosion Control
For the last several years, Rob McGann, president of Hydro-Plant
in San Marcos, CA, has had his hydroseeding crews working on beach
bluff revegetation jobs. "We probably do two a year, on average,"
McGann says, noting that getting access is the most challenging
part of the work.
Hydro-Plant is doing the reseeding for homeowners' beach bluff
lots overlooking the Pacific Ocean in San Diego County. The
residential lots range in size from one-tenth to one-half acre.
The hydroseeding follows construction of seawalls to stop
erosion, which is a serious problem given the winds and water.
Homes were built close to the edge of the bluffs, for the
magnificent views. That practice has added to the instability of
Another factor causing the high degree of erosion is the
shallowness of the soil. Some of the seawalls are built on native
"It's kind of a gamble to shoot seeds there and hope they'll
find pockets of soil to grow in," McGann says.
Installing seawalls and hydroseeding the bluffs for revegetation
fall within the guidelines of the California Coastal Commission.
This regulatory agency functions on a regional basis. The
commission has broad powers to protect the sensitive coastal
environment. It regulates what private property owners must do on
their land that adjoins the beaches.
In areas where the beaches below are open for visitors, these
hydroseeding jobs on bluff lots frequently draw the attention of
beachgoers. They crane their necks to watch the hydroseeding crew
at work with their hoses dangling from the hydroseeding equipment
at the buff's edge.
"The guys have to belay down the slopes on ropes," McGann says.
"Other times the contractors [for the seawalls] provide a
cherrypicker for us to use."
The slopes are sheer drop-offs, though sometimes there are
little walkways or ledges that the crewmembers can use. "It's
1-to-1 most of the time," McGann says.
Seeds for the beach bluff revegetation came from S&S Seeds
of Carpinteria, CA. They were all for native wildflowers and
shrubs. "We used two dozen coastal indigenous species, from Beach
Evening Primrose to buckwheat, the more common type," McGann says.
"We also included Sea Dahlia, which is unique to San Diego
For the hydroseeding mixture, "We used a heavier rate of
application-3,000 pounds per acre instead of the usual rate of
2,000 pounds," he notes. He explains that the heavier application
was necessary because of the very loose soil-lots of decomposed
sandstone. "Plus, we have wind and water erosion issues," he
The slurry contained guar gum binder as a tackifier and a humate
product for fertilizer. Germination enhancer and soil activator
were also added.
Revegetation here depends on rainfall for hydration. The Coastal
Commission prohibits homeowners from installing irrigation systems.
They can water with hoses, but water rates are high, and getting
the water to reach the plants often isn't possible.
This type of hydroseeding work is typically done in the fall,
anticipating the first seasonal rains of November and December. The
heaviest rains fall in January and February, sometimes in
The jobs typically take one day or less to accomplish. "One in
the north of the county took us three days," McGann recalls. "We
had straight westerly winds [that would have blown the hydroseeding
material away] that we had to wait out."
McGann says homeowners on these beach bluff properties are happy
to see the hydroseeding crew arrive because they know it's the last
part of work that has to be done so they are in compliance with the
Hydro-Plant's seed supplier, S&S Seeds, specializes in
native seeds and native seed blends. Victor and Susan Schaff, who
founded S&S in 1975, say climate changes have affected the
business. "The two-year drought in California has refocused the
need to use more native drought-tolerant plant seeds," Victor
Warmer temperatures have also changed the way that S&S Seeds
grows seeds for sale to hydroseeding companies, plant nurseries,
and other firms that rely on the company for high-quality native
seeds in both standard and custom mixes.
"We have had to increase irrigation at our farm during the
winter months, which typically were our wettest months," Schaff
notes. This irrigation has, of course, added to the company's
When asked about trends of recent years in the commercial seed
business, Schaff says, "There has been a tremendous increase in
seed usage to revegetate soils disturbed by solar site
installations. They are primarily using native seeds with local
S&S Seeds is a primary wholesale supplier to landscape
contractors, government agencies, and seed distributors throughout
the United States and abroad. The company keeps more than 450 acres
in seed production and also does wildland collection of seeds. That
amount of access to seeds means that customers can choose from more
than 1,000 species of native grasses, wildflowers, and shrubs. They
can order stock seed mixes or request custom seed mixes for
commercial and residential projects.
S&S Seeds will even contract to collect seed from specific
sites for a project. The seeds so collected are identified,
cleaned, tested, and stored properly. S&S employees can locate
stands of harvestable plants within the project's defined zones.
This stand assessment helps ascertain potential yield of the
plant's seeds, harvest date, and the size of collection crew
required to meet a job's deadlines.
S&S Seeds maintains a state-of-the-art seed cleaning
facility where harvested field material, after proper drying, is
taken. The dry, conditioned seed is assigned a unique lot number
and stored in the company's warehouse facility. Special long-term
storage arrangements can be made if needed. If desired, samples are
sent to an independent certified seed-testing laboratory for purity
and germination tests. Specific reports as required by the project
can be provided.
The company's acres are used not only to grow seeds for
customers and obtain a ready supply of seeds needed for specific
ecoregions, but also for research and trial fields. Both new
and old species can be easily compared for productivity, disease
resistance, and other characteristics.
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