Seed for Restoring Wetlands
By Janis Keating
an excerpt from Sprouting BMPs
Published in the May 2014 issue of Erosion Control Magazine
North of San Diego, CA, near the Del Mar Fairgrounds, I-5
crosses the 460-acre San Dieguito Wetlands. A recent $90 million
project expanded and restored this area, which has become a boon
for wildlife; ocean fish migrate in to use deeper water as
hatcheries, and the salt marsh vegetation provides nesting sites
for endangered birds. Migrating birds that travel the Pacific
Flyway also find San Dieguito a comfortable resting place.
During certain periods between 2010 and 2013, Hydrosprout Inc.
of Escondido, CA, seeded 100 acres of the wetlands. "The general
contractor, Marathon Construction Corp., did the grading, building
berms around the wetland areas," says Hydrosprout operations
manager Mark Webster. "When they were finished with a section, we'd
follow up by hydroseeding. Although there's water onsite, most of
the time we applied seed and hydromulch in the fall and winter
months to take advantage of the rains."
The hydroseeding mix included Profile Products' Terramatrix SFM
and a wetlands seed mix from S&S Seeds of Carpinteria, CA. "The
project designers came up with the specs for the mix," Webster
explains. "Seeds had to be collected within a 25-mile radius of the
project. S&S came up with the mix we needed, which we applied
at 22.85 PLS pounds to the acre."
The wetland mix included four species of saltbush (Atriplex
lentiformis lentiformis, Atriplex lentiformis, Artemisia
californica, Artriplex canescens); a native primrose
(Camissonia cheiranthifolia); Menzies' goldenbush, from
the daisy family (Isocoma mensiesii); an evening primrose
(Oenothera elata); desert broom (Baccharis
sarothroides); California plantain (Plantago erecta);
California buckwheat (Eriogonum fasciculatum); black sage
(Salvia mellifera); coyote brush (Baccharis
pilularis); heliotrope (Heliotropium curassavicum);
deer weed (Lotus scoparious ssp. scoparious); and Cuman
ragweed (Ambrosia psilostachya).
Hydrosprout's work progressed with very few hitches. "A couple
times during winter rains, the area got a little muddy, so we'd
wait. They had water onsite for us to use with the mix, so we
didn't have to truck any in. Everything we did was truck
accessible," Webster says. "In some dredge areas, we had access up
to a point, then we had to attach up to 500 feet of hose to spray
the area. We had a small problem when working around the I-5
freeway. We had to go under the bridge, and our 3,000-gallon Bowie
seeder wouldn't fit. We had to bring in a 1,500-gallon hydroseeding
machine to work that area."
Few re-dos were necessary. "There were some areas that might not
have grown as well, so we did some touchups, and in places that
were regraded we had to hydroseed again," he says. Hydrospout,
which performs jobs of all sorts, from residential to public works
and Caltrans projects, has been in business since 1988, and "we've
used S&S Seeds all that time," Webster says.
To read the full article click here.