In Hydroseeding, Weather Matters (A Lot)
Editor’s note: This article first appeared in the March/April 2016 issue of Erosion Control.
Weather can be a hydroseeding contractor’s friend or foe. It can make a job much easier or much more difficult. It played a role in each of the following varied projects done by leading hydroseeding companies across the country.
The UPMC Lemieux Sports Complex near Pittsburgh, PA, is the home of the Pittsburgh Penguins professional hockey team. The sports complex is also the first part of an innovative development that will eventually have other sections including a hotel, restaurants, and retail and office space.
The development is called Cranberry Springs. Located in Cranberry Township, PA (about 20 miles from Pittsburgh), the property covers 90 acres.
The sports complex itself covers about 20 acres. Erosion control work on the part of the property adjacent to the sports complex was done by Fossil Rock Services, located near Butler, PA.
The company does erosion and sediment control installation and maintenance projects, particularly related to Utica and Marcellus Shale energy sites. Most of its projects are within a 250-mile radius of Pittsburgh and Butler, in Pennsylvania, New York, West Virginia, and Ohio.
Most of the Lemieux UPMC Sports Complex project was done in late 2014. The final portion of the work on this section was finished in 2015.
Tom McConnell, general manager for Fossil Rock Services, says the most challenging aspect of the job was “coming up with a mix that the owner desired [and that would be suitable for the site].”
For the grassy sections, a yard lawn seed mixture was used. It contained a mix of Bluegrass and perennial rye grass. A nurse crop was not needed on these areas.
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He adds, “We were walking a fine line to meet the Pennsylvania Department of Natural Resources’ erosion control requirements and letting the wildflowers take over.”
Native wildflower seed, Flat Toe Tolerant Wildflower Mix, was used on the project. It is tolerant of the herbicide Plateau, which will be applied annually for maintenance. The seed was supplied by Ernst Conservation Seeds of Meadville, PA, the largest producer and distributor of native wildflower seeds in eastern North America.
Along with the seed, the mixture included 450 pounds per acre of 10-20-20 fertilizer and 450 pounds per acre of lime. On a small section of 2–3 acres, 70-30 hydromulch was added.
No straw was used.
The lime applied to balance the pH of the soil was Profile Products’ NeutraLime, which comes in both dry and liquid formulas. Profile’s Flexterra was also included to keep seed and the rest of the mixture in place.
“We used a fair amount of the Flexterra. It gave the protection needed,” says McConnell. He admits to being surprised at “how well the Flexterra held up through winter with minimal vegetation [established].
We had a couple of washouts, but overall it was fine.”
A nurse crop of annual ryegrass was used only on the areas that received wildflower seed. It was applied at the rate of 30 pounds per acre. Dutch white clover was also seeded, at the low rate of 5 pounds to an acre.
The seeding was done from October to November. McConnell says the weather was getting cold, “but there was enough time and warmth to get the annual ryegrass and some clover growing.”
Topsoil was added to the existing soil onsite. “It was not the greatest for planting,” notes McConnell.
All of the slopes were at a grade of 2 to 1. “We had to address erosion control issues first and foremost, and then address the desires of the owner,” explains McConnell. “We couldn’t wait that long for the stand to come in.”
Initially planted in November, the wildflowers were mostly warm-season-growing plants. None of them came up until June of the following year.
The Fossil Rock Services’ crew used a Finn T-120 HydroSeeder on the first part of the project and then finished with a C330, High Output hydroseeding machine made by Epic Mfg.
McConnell likes the Epic’s spray distance. “We get 300-plus feet. That much spray is a tremendous advantage.”
He adds, “We’ve never had it clog up. It’s totally hydraulic. The fiber mulch grinder takes the bale and cuts it off before it goes into the tank.
That decreases downtime and increases productivity.”
McConnell mentions something else that increased productivity and saved money on this job: the unexpected presence of a secure construction water meter. Having water conveniently available at the site meant “not having to go find water or pay to have it tanked in.”
McConnell says that the hydroseeding work at the Lemieux UPMC Sports Complex produced a good result. “It came in pretty decently. We were late with applying the Plateau. There were a lot of native weeds when we sprayed in August.”
There was one surprise among the favorable results. “Hydroseeders live by the cutoff date for planting. In Pennsylvania, it’s October 15. We were later than this on some parts,” says McConnell. However, “what we planted last actually came up best in the spring. It was full-blown dormant.”
Hydroseeding a Landfill
Wright’s Hydroseeding of Fayetteville, GA, hydroseeded the Safeguard Landfill in Fairburn, GA. Work on the 17-acre site began the Saturday of Labor Day weekend and ended September 21, 2015.
“We were in and out and we didn’t work every day, using a five-man crew,” says Mike Wright, owner of the firm.
The biggest challenge of the project was “the terrain and terraces. The work required dragging a lot of hoses,” he says.
In some sections, the slopes measured 2 to 1. Profile Products’ Flexterra was used on about 9 acres of the project.
“It’s expensive, but it’s good. With the amount of rainfall we had, it did an exceptional job,” says Wright.
In some areas, the work went more quickly than in others. Where soil had been removed by the construction crew, Wright’s workers were able to use it as a cap later. The soil at the landfill was Georgia’s famous red clay.
The landfill site was seeded with native grasses, including fescue, Bermuda, Bahia, and lespedeza. No nurse crop was needed. Wright’s seed supplier is Landscape Depot of Fayetteville, GA.
Wright used Triple 19 fertilizer from Beaty Fertilizer of Cleveland, TN. Liquid lime and Flexterra were also in the hydroseeding mixture.
No straw was used. For an extra degree of erosion control, a permanent turf reinforcement mat (TRM) from Western Excelsior was put in place.
For hydroseeding projects, Wright—who bought his first Finn HydroSeeder in 1987—relies on two Finn T-90 HydroSeeders. “I’ve been very pleased with the Finn equipment. We also have one of their strawblowers,” he says.
He adds, “I like their dependability. The agitation and pump units are great. We get good distance spray with them.”
Finn’s T-90 HydroSeeder offers 800-gallon working tank capacity for mid-size hydroseeding projects. This machine features hydraulically controlled paddle agitation and liquid recirculation. Operator controls are located at both the front and rear of the unit. The T-90 can discharge material up to 180 feet from the tower.
Wright is pleased with how this project turned out. “We pushed through the rain. It slowed the
project, and we moved the dates later. Now you’ll see a beautiful stand of fescue that anyone would like to have in their yard. All of the inspections passed,” he says.
Wright earned a degree in agronomy from the University of Georgia, but “got tired of that.” He switched to commercial farming, which included some erosion control tasks. From farming, he moved to full-time erosion control work.
Seeding at an Air Base
Selfridge Air National Guard Base in Harrison Township, MI, is home to the 127th Wing of the Michigan Air National Guard. A joint Department of Defense and Department of Homeland Security installation, Selfridge also hosts units from all branches of military service.
The base includes facilities for military personnel and their dependents, including a soccer field. A running path circles the soccer field. Both were hydroseeded by John Gillett, the owner of Seed Guy Hydroseeding in Port Huron, MI.
The project was done at the end of August 2013. “It was a three-day job,” says Gillett.
“Vegetation was established that fall. We had a month and a half of growing season.”
Weather during the work was not a factor, as rainfall was normal. It wasn’t exceptionally wet before the project started, nor was there an extended fall afterward. Slope was not, of course, a factor on this playing field or running path, which were made as level as possible.
When Gillett does hydroseeding work on a site that will not be irrigated—as was the situation with the soccer field and running path at Selfridge—he uses Moisture Manager, the private label version of Hydretain.
“Using Moisture Manager gets it established 30% faster than if you don’t use it,” declares Gillett.
Made by Ecologel Solutions of Ocala, FL, Hydretain is a patented blend of liquid humectant and hygroscopic compounds that attract free water molecules from the air within the soil matrix. This vapor would otherwise be unusable by plants and would eventually be lost to evaporation.
Hydretain aggregates this moisture back into a liquid form, efficiently transferring it to plant roots. Whether new vegetation is at risk because of water restrictions or lack of rainfall, Hydretain/Moisture Manager can provide the moisture needed at this critical stage of growth.
The seed used for both the soccer field and running path was a 50/50 blend of Bluegrass and turf-type perennial ryegrass, “typical seed mixture for athletic field use,” says Gillett.
“Seldom do we use an annual rye as a nurse crop, only in cold weather where it isn’t warm enough for regular germination,” explains Gillett, whose seed suppliers are John Deere and La Crosse Seed in La Crosse, WI.
Besides the seed, water, and Moisture Manager, the hydroseeding mix on this project included a nonbranded mulch of 20% wood fiber and 80% paper cellulose. Fertilizer in a ratio of 18-24-12 from John Deere was also added.
No straw or blanket was needed. The sandy, loam type soil with clay subsoil didn’t require a soil amendment.
“Guar was already included in the mulch. The land was flat, so we didn’t need to add a tacifier,” explains Gillett.
A landscaper for 20 years, Gillett got into hydro-seeding because “I wanted to downsize and specialize in one thing.” He uses two Finn HydroSeeders, 300- and 3,000-gallon models. He has also fabricated his own hydroseeding equipment.
To continue reading the full article, which includes additional case studies and in-depth reporting, check out the March/April edition of Erosion Control. Please click here. You may need to log-in or subscribe to our magazine.