Seeds of a Certain Sort

Tuesday, January 01, 2013

 By Janis Keating

September-October 2011

Erosion Control, the official journal of the International Erosion Control Association

Seeds Quick to Grow, Plants Slow to Burn
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 Seeds."

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 resistance.

"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 well."

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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