During the Middle Ages, alchemists were convinced that they had the solution to the world’s problems. All they had to do was figure out the formula for the right mixture. They were trying to turn ordinary substances, particularly straw, into gold.

Hydroseeding is several centuries and much scientific knowledge removed from alchemy. But it has a kind of magic to it as well. To perform hydroseeding successfully takes knowledge of chemistry, plants, soil, machinery, and more.

The magic results from the right combination of ingredients, the right mixture for a particular situation of new seeding or revegetation. As author Tom Wolfe wrote of the original seven American astronauts, it takes “the Right Stuff.”

The following hydroseeding projects show that the right mixture-seed, soil stabilizer, tackifier, mulch, water, fertilizer-makes all the difference. Add in the unknown factors of variable weather, remote and rugged terrain, state and federal regulations to meet-and, occasionally, dangerous wild animals.

Seeding a Solar Site
Norm Gray of Transit Seeding in Medfield, MA, serves as the current [resident of the International Association of Hydroseeding Professionals (IAHP). Gray has been in the hydroseeding business long enough to have worked on many different types of projects.

Photo: Varsity
Compost- and mulch-filled socks were used for sediment control.

Transit performs hydroseeding for customers within a 50-mile radius of Boston. “Once in a while we trip up to Rhode Island or Connecticut for a job,” Gray says.

One of Transit’s recent projects was revegetating sites that are being developed for solar power collection. This work followed site grading by the Rezendes family’s site construction firm. The two companies have worked on numerous projects together over the years. “I call it a marriage,” laughs Gray.

On the solar sites, the stanchions that hold the solar panels are set up in rows 300 to 500 feet long. All of the panels are oriented in the same direction.

“They’re laid out so close to each other in regimented form that you can’t get your vehicles between them,” Gray says. “The hoses have to be pulled out 300 to 500 feet, making the job somewhat more labor-intensive.”

Such jobs would typically be handled by two crewmembers, but three or four are needed to handle the extra work with the hoses. Mindful of saving time for both hydroseeding companies and the contractors, Gray has a person talking with the contractors about the problem.

“People who are building the solar sites want to put in the stanchions first. I’ve been lobbying for the hydroseeding to be done first, and then the stanchions installed after we’re done,” Gray says. Another benefit would be elimination of any possible overspray of the hydroseeding mixture on the solar panels. They must be kept clear for full efficiency.

“Generally, they specify seed types that grow low plants that don’t need maintenance-no mowing,” Gray says. “That tends to be hard fescues.”

Transit Seeding uses a specific seed mixture created and marketed for solar fields, with seeds native to New England. It comes from Ernst Conservation Seeds in Meadville, PA. The mixture comprises 30% Salem creeping red fescue, 30% whisper sheep’s fescue, 15% heron hard fescue, 7.5% Chariot hard fescue, 7.5% Matterhorn hard fescue, and 10% annual rye grass.

“Everything in the fescue family does well in New England,” Gray observes.

The fertilizer added to the hydroseeding mix was 18-20-12. It’s a 25% organic fertilizer with the nitrogen derived from natural sources. The mixture also contained a cellulose fiber mulch and tackifier measured to the manufacturer’s suggested rate of application.

Weather wasn’t a problem with hydroseeding at the solar sites, because it was warmer and drier than usual. It did, however, bring about one slight change in the work.

Photo: Varsity
Varsity Landscaping revegetated natural gas fields at a Marcellus Shale site in northeastern Pennsylvania.

“Because of the unusual seasonal warmth, the contractor asked us to put in extra annual rye grass in case the warmer days and nights might encourage it to generate early,” Gray says.

The warmer weather of 2012 had a positive effect on Gray’s overall business. “Normally our season ends about Thanksgiving, but we did our last job of the year on the day after Christmas,” he says, adding that a 2-acre job was scheduled soon afterward in January.

No mats or blankets were used on the solar sites. “They’re not used very often, up here,” Gray says. “You don’t see them until a slope gets greater than three to one, or occasionally in a swale where they’re anticipating some water.”

He notes that contractors and other customers sometimes ask whether the hydroseeding should be done before or after blankets are put down. “We suggest they do the hydroseeding before the blankets are down,” he says. “The seeds generate better.”

Soil at the solar sites is generally a topsoil mixture with some organic content. “We screen loam on residential work for nothing bigger than 1 inch on the surface,” Gray says. “Natural loam a bit rougher on a solar site is acceptable-not a problem for seeding.”

Transit Seeding uses a Bowie Imperial 3000 Hydro-Mulcher for the solar site work. “We’ve been operating Bowie machines since 1964,” Gray says. “We replace them every nine, 10, 11 years.”

Gray believes that maintenance of equipment maintenance is essential. “We’re strong on doing our own maintenance. We use the winter season to refurbish our equipment, so come spring, we have equipment that will be ready to go and reliable.”

He adds, “We pride ourselves that it’s pretty much a forever relationship with our customers. We have a long list of loyal followers who’ve been with us for 10, 12, 15 years. We still have one customer that dates from 1951, the first year we were in business.”

Gray’s father started the business by building hydroseeding tanks in the shop at his welding business. He later expanded the business to include landscaping services, but when his son took over in 1982, he decided to specialize in hydroseeding work.

Now Norm Gray III is working for the company. “He’s Mr. Outside and I’m Mr. Inside,” says Gray. A loyal Patriots’ football fan, Gray says he’s tempted to refer to his son as “NGIII, like RGIII.”

On Campus
Football fans of Ohio State University in Columbus are proud of their stadium. Known as “The Horseshoe,” it is one of the best-known landmarks on this large campus.

Penlin Seeding in Columbus, owned by Chris Pence, does many hydroseeding projects all over the state, including Columbus. Some of the company’s local projects are at Ohio State.

The 17th Avenue Improvement project is just south of The Horseshoe, on the south and southeast corners of the street. This topsoil respread job involved hydroseeding along vast stretches of street area: 11,200 square yards.

Penlin Seed’s crew had to work in the midst of heavy street traffic and pedestrian traffic. Because the crew could work only on weekdays, it finished in September 2012, after football season began.

Penlin used a specific grass mixture call Grid Iron Mix, a sports field grass seed mixture from the Seed Center in Delaware. “We use it a lot at Ohio State,” says Brandon Hines, Penlin’s foreman.

“We broadcast our seed first on the ground because we get better adherence. Then we spray the hydroseeding mulch on top of the seed,” he explains. “We also put a small portion of the seed in the hydroseeding mulch-that’s to cover in case you miss a spot during the broadcast of the seeds.”

The 17th Avenue project was one of high visibility, so full seed coverage was a priority. With so many people walking to and from the stadium, the area came under close scrutiny. The Penlin crew installed temporary fences to keep the newly seeded area from being trampled.

Weather was in the 80s, warmer than normal, when the work was done. Pulverized topsoil was brought in for the seeding. Finn Corp.’s HydroStik was added to the mixture. Penlin uses both Finn’s HydroGel and the company’s HydroStik. HydroStik is a guar gum-based tackifier for use on normal to moderate slopes. It bonds the seed and mulch to the soil. HydroGel is a polymer that can store water and nutrients up to 500% of its weight and size; it replenishes itself with the next rain and is especially useful to keep plants growing when moisture is low to inadequate.

“Two of the areas had pretty good slopes-about 3 to 1,” Hines says. “We add an extra bag of tackifier with the mulch on sloped areas, but we don’t use blankets or mats.”

A second hydroseeding project at Ohio State involved OSU bridge and street improvements. After the university replaced curbs and intersections, Penlin’s crew made the green areas green again.

“This project required a lot of soil prep,” Hines says. “We used a Harley rake and a John Deere power rake, the PR96B, which was attached to a skid-loader. The 96-inch-wide blade can tear up an inch of soil and winnow rocks to the sides of rows, where they can be picked up later with a RockHound.”

For this job of about 5,000 square yards, Penlin used its own seed blend. “We use a lot of Beauty Lawn,” Hines says. Beauty Lawn is a bluegrass and fescue mix, with 20% perennial rye grass, 30% creeping red fescue, and 50% Kentucky bluegrass. HydroStik was added to the mixture.

Hines says that the most challenging part of this job was working along ditches. “Most of our equipment is large, with 5 feet across being the smallest. The ditches were 2 and 3 feet wide. It took a lot of hard work and a lot of topsoil respreading.”

Penlin added erosion control blankets on some of the ditches. One ditch, however, later completely washed out. “We ended up rip-rapping it,” Hines says.

A third Ohio State hydroseeding project for Penlin was just north of the campus, at the OSU School for the Blind. This project was also done in 2012. The project covered 20,992 square yards, or about 4.3 acres.

For this new project, all site grading was at plus or minus 1 inch. “Two inches is normal. Anything over 2 inches, we remove,” Hines says. The hardest part of the work, he notes, was “a lot of rock-hounding in a lot of small areas.”

Photo: Varsity
Compost- and mulch-filled socks were also placed around ponds.

The rate of seeding was 8 to 10 pounds per 1,000 square feet. HydroStik was added to the mixture. Penlin had a custom seed blend made up for this job, consisting of four different types of tall fescue. The soil was all topsoil respread, used from the site, and not pulverized. Neither netting nor mats were needed.

The weather in September was hot, and no rain fell. There wasn’t a great deal of vehicle or pedestrian traffic, but there was a lot of construction going on at the same time. A status of “high safety” required that the Penlin crew wear reflective vests and safety glasses.

Ohio State has another famous landmark besides The Horseshoe stadium. “The Oval” is an 11-acre green area in the midst of the main campus. Reseeding The Oval was one of the largest hydroseeding projects in Ohio, and it was one of Pence and Penlin’s first hydroseeding jobs.

Natural-Gas Fields
Varsity Landscaping has been in the hydroseeding business for some 30 years. Since 2010, the company has been revegetating sections of natural gas fields in the Marcellus Shale section of northeast Pennsylvania. The work is expected to be ongoing for some time.

Varsity’s work there includes pad sites ranging in size from 4 acres to 25 acres, as well as sections along pipelines. Seed mixtures vary.

“We use whatever the company wants us to use, all mixes of native seeds,” says Al Nocerine, project manager for Varsity. “Usually we take a soil sample and send it to Profile Products for testing. They recommend what we need to use.”

Sometimes, the natural-gas companies request alfalfa and other “biological mixes” to provide food for wildlife. These plantings are often done in 75-foot-wide strips along rights of way.

Mats and blankets are used if needed. “We did a 40-mile pipeline, all blown with straw and matting,” Nocerine says. Using matting or straw “depends on what the specs call for.”

Weather doesn’t affect the work much. “Last year we sprayed right through the winter,” Nocerine says.

The most challenging part of Varsity’s work on these sites is accessibility. “Some slopes are 1:1,” Nocerine explains. “We had to put our hydroseeding equipment on a D8 bulldozer and then lower it over the side of a mountain with a winch cable.”

A lesser challenge is provide by the area’s rattlesnakes. “We use black SiltSoxx filled with mulch to filter water,” Nocerine says. “The black color and the mulch generate heat and attract the snakes.” The solution is to call in a snake trainer to remove the snakes first. When the hydroseeding work is finished, the snakes are brought back and released.

Photo: Innovative Landscape Technologies
Slope-stabilization projects can range across a wide selection of terrains.

For the adherence of seed, especially on the steep slopes such as those within the Marcellus Shale project areas, Varsity Landscaping relies on Flexterra from Profile Products of Buffalo Grove, IL. Flexterra is a flexible growth medium made of wood fibers, and it bonds easily to soil.

“We just did 6 acres on a very steep 1-to-1 slope with Flexterra,” says Nocerine. “They [the client] were impressed. It worked very well.”

Varsity also uses Profile’s Pro Matrix and other products. “We like the additives, too-Jump Start, BioPrime, Neutra Lime,” Nocerine says.

Jump Start, with its more than 200 species of beneficial bacteria, accelerates the establishment of vegetation. It contains humic acid, a soil penetration agent, so that it can improve moisture, infiltration, and retention, thus making seeds generate more quickly. BioPrime enhances the long-term sustainability of vegetation. Rated at 18-0-0, it contains slow-release nitrogen, humic acid, seaweed extract, and endomycorrhizae. The slow-release (nine to 17 months, depending on environmental conditions) of nitrogen is especially beneficial for establishing vegetation on bare soils. Neutra Lime is a soil neutralizer. Containing highly concentrated dry limestone, it can create one point of pH change within 10 days of being applied.

Working Across Ecozones
Dangerous animals are also present in areas being hydroseeded by Hydro-Plant Inc. of San Marcos, CA. Safety classes for workers stressed awareness of rattlesnakes and the possibility of mountain lions. So far the snakes have been spotted, but no mountain lions-only the tracks they left.

Hydro-Plant is hydroseeding a utility corridor that stretches from east of San Diego to the coast. The crews are revegetating and providing erosion control following the installation of aboveground power towers for different utility systems.

“The weather’s been a big factor on this job,” says Rob McGann, president of Hydro-Plant. “In southern California we don’t usually experience high winds and rain storms like we’ve had.” On some winter days, the wind chill temperatures dipped into the high teens.

To the wildlife and the cold, wet weather add the difficulty that remoteness brings. “Some sites were basically off-road so that we had to truck water in from miles away,” McGann says.

Work sites ranged from 5 to 30 acres, and each was different. McGann says best management practices (BMPs) varied among the sites. Work covered five distinct ecozones: coast, foothills, mountain, mountainous-desert, and desert. Seed mixtures for each distinct ecozone within the project were custom-blended by S&S Seeds in Carpinteria, CA, a company that specializes in native and rare seeds. Choosing and then obtaining the exact seeds meant working far ahead of the project. “We had some nurse crop seed,” McGann says.

Photo: Varsity
Varsity applied Flexterra on the steeper slopes.

Soil types varied from sand in the desert ecozone to some areas with limestone deposits. No soil additives were used. “The environmental consultants [working] with us wanted the sites to be as close to their natural states as possible,” McGann explains.

Except for seeds specific to a particular ecozone, the mix-water, mulch, and tackifier-was “pretty much the same on all sections,” McGann says. “On the flat sites the tackifier was more for fugitive dust prevention.”

For the tackifier, the Hydro-Plant crews used Super Tack, a dispersible, biodegradable guar gum tackifier from Rantec Corp. of Ranchester, WY. Super Tack improves pump performance and keeps the slurry mixture flowing smoothly. It mixes easily and is safe for the environment.

Slopes were rarely greater than 2 to 1. Coir blankets were used in some areas. Wattles were also used in some sections.

In the arid regions, the Hydro-Plant crews used imprinting, or mechanical seeding. By creating tiny microclimates, the resulting seedlings had a much stronger chance of thriving.

The most challenging part of this utility corridor project was managing access to the remote areas. Reaching these areas in the future will require using helicopters.

“They had to regrade the road so that we could move our equipment,” McGann says. “They were closing the road behind us. We had to get it right the first time.”

These hydroseeding professionals prove that the magic of their successful projects is in the mixtures they use. While the results look like magic that would delight the old alchemists, they come about from knowledge, experience, and a lot of hard work. 
About the Author

Margaret Buranen

Margaret Buranen writes on the environment and business.