By Janis Keating
Erosion Control, the official journal of the International
Erosion Control Association
Seeds Quick to Grow, Plants Slow to
HydroPlant of San Diego, CA, has been around since 1978,
seeding for native wetlands, mitigation projects, residential
areas, roadsides, and mine reclamation. "We also do golf courses,
big turf areas, schools, and parks, and the seed mix we use
varies," says president Rob McGann. "But the seed company doesn't.
For at least the past quarter century, we've used S&S
S&S Seeds in Carpinteria, CA, offers varieties for
reclamation and erosion control, native and turf grasses, ground
covers, and pastures. Looking for a specific plant? The company's
database allows searches by scientific or common name, as well as
searches based on one or more specific plant characteristics. Users
can search for plant selections based on height, inflorescence
size, flower size, flower color, flower type, bloom time, growth
type, life cycle, California natives, ranges within California,
water requirements, salt tolerance, and low-fuel/ fire
"Seventy percent of what we do is native seed-but, defining
that? There are seven or eight categories; it depends on who's
writing the specs and the application," McGann says. "For example,
the roughs on golf courses might be different than highway roadside
plantings. Then, too, California has many different ecosystems-from
coast to inland valleys to mountains to desert-and all have
different plant communities. Lots of jobs we bid on, specifically
those calling for 'coastal sagebrush mix,' require seed collected
within 25 miles of San Diego."
McGann says the numbers of different mixes he uses are "easily
in the dozens. On a golf course, we might apply two or three mixes,
perhaps eight or nine mixes. On a large mitigation site, we might
have seven or eight different mixes to apply. The site designer
puts seed specs on the plans, and crews put out flags-or they might
chalk or paint out the areas-showing us where which seed mix goes.
And sometimes a site is so sensitive, special supervisors are on
hand. On many Caltrans projects, everything needed for hydroseeding
comes to the job site unmixed, and the supervisor watches us mix
it. Sometimes a biologist wants to watch us mix it there, as
HydroPlant also works in other states. "You go over the hill to
Arizona, and the seed mix changes drastically. It uses nurse crops
or pioneer plants, which come up very quickly. Shrubs and so forth
come in later and are the permanent vegetation, which are also in
the mix. Native shrubs can take up to five years to grow."
Standard, as well as site-specific, amendments are added to the
hydroseeding mix. "We use 100% wood-fiber mulch and colored green
dye. If a soil test indicates a need, we'll add fertilizer to
adjust the N-P-K ratio, or add gypsum to bring down soil pH."
McGann's firm also does much temporary seeding on construction
sites. "Places being graded, due to stormwater regulations, must
receive temporary seeding. As some areas are hard to get to-our
work varies in remoteness of sites. Sometimes we have to drag 1,500
feet of hose. A continuous flow pump keeps up the pressure so we
can get the job done.
"Speaking of remoteness," he continues, "on a recent job for a
big electric utility, several work sites were located in the back
country. I spent nine hours riding around in the truck, looking at
the sites. We could do only one or two sites a day, because each
was so remote; it took more time to get to the site than work on
it. The sites themselves were very small, and each had different
ecosystems. On this job, we took our big truck for use as a water
tank, then pulled smaller, 600-gallon hydro-trailers behind a
tractor to get to the site. We needed the power of a tractor to get
up and down the hills."
What's the biggest change he's seen in the industry?
"In the past few years, it's been the change to natives," McGann
concludes. "The issue of water and drought is crucial here. We're
using more natives because they're usually drought tolerant. We
also need to heed the list of plants prohibited by fire districts;
there's no sense in planting things that burn easily."
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