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What is in a hydroseeding mixture is dependent on several factors such as consumer choice and prevailing conditions of the area to be hydroseeded. The base components of hydroseeding mixtures contain several ingredients, grass seed, fertilizer, water, and mulch, and are the principal elements used in hydroseeding, however, other elements can be added depending on requirements and site circumstances.
Hydroseeding is a very useful and efficient way to add some color or texture to your lawn. You can mix different colors of seeds together to create a unique pattern. You can also add different fertilizers to ensure healthy grass growth and mulches to bind and protect the soil.
However, the exact mix you choose will have as much to do with local conditions and soil quality as with consumer choice. Below we will look at the various components of a hydroseed mix and discuss their uses and benefits as well as when to employ them in a project.
Different Types of Hydroseeding
The flexibility to apply a variety of slurries is one of the numerous benefits of hydroseeding. One distinction between hydroseed combinations is the seed used. You could choose one variety of seed for a dazzling front lawn and another for shadier locations.
You may even utilize wildflower seeds in hard-to-mow portions of your yard. Take into mind your habitat and climate, since some seed kinds will not thrive in particular regions.
There are further variants to the hydroseed mixture/slurry that can be created, such as various fertilizers or even color dyes.
Grass Seed Used in Hydroseeding
When choosing grass seed, there are generally three types of seed to choose from cool-season, warm-season, and Bermuda. Cool-season grass seeds are generally sown in the spring and before the heat of summer, while warm-season seeds are generally sown in the fall or early spring. Bermuda grass can be sown year-round.
Grass Seed Mixes for Hydroseeding
Almost every sort of grass seed, as well as wildflower mixtures and even oats, may be sprayed with hydroseeders, and often a mix of different varieties is used.
In order to get the best results when seeding your lawn or grass area, it is suggested that you use around 5-10 percent annual rye seed in the seed mix. This seed will germinate and sprout more quickly than the other types of grass seed in the mix, and it will also retain and bind the soil in place until the other seeds have had enough time to germinate.
One key benefit of this is that will provide some green ground cover in as short as seven days. Caution should be used when using an excessive amount of annual rye, as it can crowd out the main variety of seed you are trying to establish.
Grass Seed and Erosion Control
Some grass varieties bind the soil more effectively than others. As such it is possible to do a variety of erosion control tasks using the various seed types and by choosing the most suitable seed for the job.
Each situation is different but if you are prone to soil erosion then discuss this with the contractor when deciding on the seed mix.
Mulch and Its Purpose when Used in Hydroseeding
Aside from seed type, the most significant distinction between slurries is the kind of mulch used.
What is the significance of mulch in the hydroseeding mixture?
Hydroseeding is only feasible because of mulch! It’s easier to spray a combination with wet mulch since it’s heavier than a mixture of seed and water.
There are several ways in which mulch assists in the development of a plant.
Mulching helps reduce the evaporation of moisture from the soil, helps maintain an even soil temperature, reduces weed growth, and adds organic matter to the soil.
A cover (often referred to as a blanket) is formed over the seed mixture as it settles on the ground after application. It serves the purpose of keeping the seed in place, protecting it from adverse weather, and it helps kick-start seed germination.
In addition, mulch will mitigate possible erosion because of the protection the mulch blanket gives.
What types of mulches are used in hydroseeding?
There is a large variety of mulches available, ranging from wood-based mulches to special erosion-prevention mulches. Below are listed the most commonly used mulches although there are many other specialty mulches that can be used depending on circumstances.
Wood Fiber Mulch
Wood fiber mulch is more costly mulch than others, but it performs a better job of avoiding erosion and fostering plant development than the latter. Wood mulch is particularly good for sloping lawns and is often used when looking to produce high-quality lawns.
Paper mulch is a cost-effective mulch addition that is particularly well suited for situations in which keeping costs under control is a priority and quality is a secondary consideration. For flat wide fields near industrial zones or highway medians, as well as certain yards, this method is beneficial.
Wood/Paper Blended Mulch
A wood/paper mix split 70/30 between wood and paper provides greater erosion control and encourages better grass growth than paper mulch on its own but at a more reasonable cost than using 100 percent wood fiber mulch.
When compared to other mulches such as wood, paper, or blended mulch, straw mulch uses less water, is simpler to put into the hydroseeding tank, and can produce a more uniform layer of covering.
Cotton Fiber Mulch
According to a study done by the Department of Agronomy at Auburn University, cotton fiber mulch establishes seed quicker and promotes the growth of grass better than wood, paper, or erosion control blankets. Cotton is permeable, absorbent, and biodegradable by nature, making it the ideal material for reducing erosion and growing seedlings.
Erosion Prevention Mulch
Erosion prevention, as the name suggests, is specially formulated mulches that help prevent erosion. These tend to be used in areas that might be particularly prone to erosion such as slopes or water-adjacent areas. They often include binders and synthetic polymers for soil stabilization.
The mulches used can be bought commercially and generally come in compacted 50-lb bales. These bales will often include a dye to aid with application uniformity when the mulch is sprayed.
A specific manufacturing technique is used to create certain mulches, which enables them to be discharged directly into the hydroseeding tank.
Certain mulches are manufactured to include synthetic fibers and or tackifiers. These are added to improve the abrasion resistance of the mulch.
Another element commonly added to a hydroseed mix is tackifiers. These provide a useful role in helping the operation of the process go more smoothly and helping with possible adverse weather conditions post-application.
The use of hydroseeded tackifiers accomplishes two goals. In the event of rain, even heavy rainfall, they will act as glue, holding the seed and mulch in place until the weather improves. They also serve to lubricate and make the system more slippery. This enables the hydroseeder to work more efficiently and allows the operators to utilize greater quantities of mulch in the tank while also reducing the likelihood of blockages in a hydroseeder system.
A few of the goods that are used to make tackifiers include polyacrylamide, which is applied at a rate of 3 pounds per acre and is simple to store and economical, as well as Guar, produced from the gum of the Guar tree and used to make tackifier. Guar is typically sprayed at a rate of around 30 pounds per acre.
Fertilizers Used in Hydroseeding
In most cases, you may use whatever fertilizer you choose with a hydroseeder. This comprises granular, water-soluble, and liquid formulations, among others.
That being said it is probably best to avoid using an agricultural fertilizer as it is not suitable for the application. Commonly, a high phosphorus beginning fertilizer is recommended. This is because phosphorus is important in terms of establishing a healthy root structure.
Despite this many people look to use a balanced fertilizer, such as a 19-19-19. If using a balanced fertilizer it is important to bear in mind that the higher the values, the less filler there is in the fertilizer.
A further point to consider if you are building your own hydroseeder is the nitrogen levels in the fertilizer. Nitrogen is particularly corrosive and thus might damage a metal tank. If possible try to use a poly tank as this negates the issue.
Types of Fertilizer
There are various types of fertilizer that can be utilized for hydroseeding mixes
Water Soluble Fertilizer
Water-soluble fertilizer is formulated to dissolve quickly in water. These are often in powder form and blue in color. These fertilizers are often a bit more costly than traditional granular fertilizers, and they are not typically used as a time-release fertilizer, either. Water-soluble fertilizer when used in conjunction with hydroseeding allow, the nutrients to quickly penetrate the seed’s outer layer and kick-start the germination process.
Fertilizer in liquid form has many of the same benefits and drawbacks that water-soluble fertilizers do. The distinction is that it is already in concentrated liquid form, and it must be diluted with water before it can be used as intended.
The ingredients used in organic fertilizer include natural ingredients like bone meal, dried blood, dung, kelp, and seaweed, among others. They are particularly popular among gardeners and those who don’t want to use synthetic pesticides. Organic fertilizers are generally more costly than inorganic fertilizers and can have fewer nutrients.
Water in the Hydroseed Mix
Water plays a crucial role in the hydroseed mix. Not only does it help bind the various elements together but water serves as both a transport for the mixture and a source of moisture for the soil.
Generally, water makes up between 5-10 percent of the volume of the hydroseed mix. The mix must be able to retain sufficient moisture to allow for the appropriate and quick germination of the grass seed varieties while also providing a cover to avoid soil erosion.
Summary: What Is in Hydroseeding Mixture?
As you can see what is in a hydroseeding mixture can be quite complex. The resulting mix will be dependent on consumer choice as well as prevailing conditions of the application area. Even having pets can sometimes impact on the choices for the hydroseed mix.. Each element, whether mulch, grass variety or fertilizer should be considered individually.
Hydroseeding is a relatively inexpensive way to improve the appearance of a lawn or grass area. It is also a useful way to efficiently create a new lawn area around buildings, parking lots, and other outdoor structures.
 Richard Guthrie, Director Auburn University: Cotton Research Report
 Department of Forestry, Faculty of Forest Science, Gorgan University of Agricultural Sciences and Natural Resources: Effect of hydroseeding on grass yield and water use efficiency on forest road artificial soil slopes