Hydroseeding 101: What Is Hydroseeding?

hydroseeding 101 what is hydroseeding. A large hydroseeder with dual booms sprays green hydroseed over a field.

Hydroseeding is a process where seed and any combination of fertilizer, lime, biostimulants, moisture retention polymers, tackifiers, and other additives are combined with water and a hydroseeding mulch to form a slurry that is sprayed onto the ground to establish vegetation and control erosion.

These ingredients are mixed in a truck or trailer-mounted tank that contains either a jet agitation system or a mechanical agitation system which creates a homogeneous slurry that is then transported to the job site and sprayed over prepared ground in a uniform layer.

Hydroseeding has grown in popularity in many industries, including the landscaping, construction and erosion control industries, to name a few. This popularity in recent years has come as professionals in these industries recognize hydroseeding for its speed and efficiency. 

In turn, businesses offering this service and equipment required for effective hydroseeding operations have experienced increased demand. However, few people know much about the hydroseeding process and why it works as well as it does.

To successfully provide effective hydroseeding services, it’s important to learn everything you can about the process and what to expect out of it. It’s also important to understand what to look for in high-quality hydroseeding equipment, so your hydroseeding service has the best tools for the job. 

To help, we’ve put together this detailed outline of the hydroseeding process, its components and what to look for in hydroseeding equipment.

What are the Benefits of Hydroseeding?

Hydroseeding offers many advantages over conventional seeding processes.

  • Lawn Types and Varieties: Spraying seeds over a lawn means you can plant on nearly any kind of surface — flat, sloped or uneven. The slurry not only evenly coats these terrains, but also ensures the seeds stay in place.
  • Time Efficiency: Spraying on grass seed is much faster than manually spreading seeds, taking half the time of conventional seed spreading. Seed growth is also much faster due to the nutrient boost from the slurry, taking about a week on average to show the first grass shoots
  • Slope Stabilization: Roots provide a stable base to hold back dirt and keep it in place despite gravity or erosion. Hydroseeding and hydromulching also accomplish this by binding to the ground and holding fast as the seeds germinate and take root.
  • Erosion Control: As the slurry dries, it hardens, protecting the seeds from movement and wind or water erosion. This prevents patchiness and helps develop complete lawn coverage over uneven terrain.
  • Labor Savings: One of the largest cost-saving advantages to hydroseeding is the reduced labor costs. This is because all of the ingredients needed for the seedbed are included in the slurry and applied at the same time. Conventional seeding methods typically require applying each ingredient separately. Additionally, conventional methods using straw or hay need to have that covering removed once the seeds establish themselves, increasing the labor input. Hydroseeding eliminates this requirement because the mulch breaks down and becomes a beneficial part of the soil over time. 
  • Cost Reduction: Hydroseeding can be around a third of the cost of the price of sod, and significantly lower than most other conventional methods, especially for larger projects.

Virtually any grass or ground cover that can be planted by seed can be hydroseeded. This includes any sun or shade lawn seed, athletic field mixes, pasture mixes, native grasses, wildflowers, roadside mixes and erosion control mixes. In order to provide this type of lawn service, it’s important to find high-quality Hydroseeding Equipment for sale to offer outstanding performance.

How Hydroseeding Works

The key to the effectiveness of hydroseeding is the mulch that acts as the growth medium for the seed. When the right mulch is applied at appropriate rates, the mulch provides moisture retention for faster germination, insulation from temperature extremes to prevent seed dormancy, and protection from erosion. Unlike hay or straw that is frequently specified on seeding jobs, hydroseeding mulch contains no weed seed.

Hydroseeding slurry consists of the following main ingredients:

  • Water: Water acts as a carrier, and is an important molecule in the growth and development of the seed, prompting the germination process. 
  • Seed: The seed used in a hydroseeding mechanism can be anything from a basic lawn grass seed to a wild grass or wildflower seed. Nearly any seed can be used with this planting method. 
  • Fertilizer: Fertilizer is usually included in the mix as a stimulant for root growth. Other types of fertilizer include different ratios of chemicals to encourage different types of growth.
  • Mulch: The mulch lends quite a bit to what hydroseeding looks like. Hydroseeding mulch helps to protect the seed and seal moisture in the slurry. It can be wood, paper or a mix of the two, and is often dyed to ensure the mix is applied completely and thoroughly. This mulch is usually dyed green, both to ensure the entire ground is covered and to blend in with the grass as it begins to grow.
  • Other Additives: Other products added to the hydroseeding slurry include tackifier products, which help it to adhere to slopes during rainy conditions. They also help to seal moisture into the soil. 

The slurry is mixed in a tank, creating a homogenous mixture so when the slurry is sprayed over the ground, it covers the ground evenly. 

A great advantage of the hydroseeding slurry is that it can be adjusted with various additives to create the ideal growth environment for the seed. The other big advantage of hydroseeding versus conventional seeding methods is the labor savings. This is because all of the ingredients that you want to apply to the seedbed are combined into the slurry and applied at the same time.

Types of Mulch That Can Be Included in a Hydroseeding Slurry

There are several different types of hydroseeding mulches available today and the selection is constantly growing. Each type of mulch has its place, whether it is tacking straw, low cost lawn establishment, premium lawn establishment, slope stabilization, severe erosion control, or alternative daily cover on landfills.

Price, application, and local availability usually are the driving factors in choosing the ideal hydroseeding mulch. Hydroseeding mulch usually comes in 40 – 50 pound bales and contains a dye to help you achieve an even application.  Most mulches come in a compressed bale that must be broken up by hand or by the hydroseeding/hydromulching machine.  Some mulches are manufactured with a special process that allows them to be poured into the tank. Additionally, some mulches contain additives such as synthetic fibers or tackifiers. Check out a list of some of the more common hydroseeding mulches on the market today: 

  • Paper Mulch
  • Wood Fiber Mulch
  • Wood/Paper Blend Mulch
  • Pourable Mulch
  • Straw Mulch
  • Cotton Fiber Mulch
  • Erosion Control Mulch – BFM’s, FRM’s, EFM’s, SMM’s, etc.
  • Alternate Daily Cover – Used on the working face of landfills

What Is the History of Hydroseeding and Hydromulching

Hydroseeding began in the United States during the 1940s, when Maurice Mandell from the Connecticut Highway Department found that by mixing water and seed together, the difficult to reach slopes of the Connecticut expressway could be seeded by spraying the mixture over them. Later, in the 1950s, Charles Finn constructed the first commercial hydroseeding unit which included a mixing tank to combine the seeds, water and other additives, and a pump to spray the mixture over large areas. 

At the time, the construction of the new Interstate Highway System by the Eisenhower administration changed the way roads were built across the United States. Instead of running roads around or over hills, these new road systems went through them, resulting in excessively steep hillsides, which were next to impossible to seed with conventional methods. The hydroseeder was a response to this new need, spreading seed quickly and efficiently along highways while simultaneously helping prevent erosion.

The new technology, armed to handle steep slopes and rough terrains, spread quickly throughout the United States as a way to seed these hard-to-landscape places, and they only grew in popularity as people noticed that the grass planted with hydroseeding grew faster and better than the grass planted with conventional methods.

The earliest hydroseeding machines used a jet system with peat moss as the mulch agent. The machines worked well, but were prohibitively expensive, so only big seeding jobs justified using them. As time went on, methods and manufacturing improved enough to see more affordable hydroseeding machines hit the market, especially as demand increased for a quick and easy solution to the grass planting needs of the nation.

For example, soon after hydroseeding gained popularity, straw blowers came onto the scene. These machines sprayed straw-based mulch over the seed planted with hydroseeders, protecting the seeds from temperature extremes while preventing erosion and retaining moisture.

These advancements and developments paved the way for the hydroseeders and hydromulchers of today to rise up in the landscaping world.

What Industries Use Hydroseeding? 

Many industries use hydroseeding for a number of applications, including the following:

  • Residential and Commercial Landscaping: Hydroseeding can create a beautiful lawn for any residence or business, growing a healthy, well-protected and long-lasting lawn.
  • Landfill Covers: Landfills can be difficult to cover over, and require a healthy root system to prevent movement of the contents beneath. Additionally, hydromulch can provide the nutrients often lacking in landfill soil. 
  • Mine Reclamation: Like landfills, mines often have nutrient-poor soil, which requires a good deal of support for anything to grow. Hydromulch can make up the difference.
  • Roadsides: Roads often cut through a variety of terrains, and high vehicle speeds create some amount of wind, which causes erosion over time. A hydroseeded roadside can settle into any slope and simultaneously prevent erosion due to wind.
  • Athletic Fields: Athletic fields are large areas that require a level and evenly covered playing field to prevent player injuries. 
  • Fire Suppression and Revegetation: Hydroseeding can help establish new growth even in seemingly unforgiving or barren environments. Hydroseeding can help establish plant life within firebreaks, or reestablish plant life in a burnt area.
  • Waterside Stabilization: Rising and falling water can take a toll on coastlines and stream banks, eating away at the soil. Roots from grasses and other plant life can protect against such erosion, especially grass grown with particularly erosion-resistant hydromulch. 

Jet Agitation vs. Mechanical Agitation

One of the biggest decisions you must make when purchasing a hydroseeding or hydromulching machine is what type of agitation system you will need. There are two types of agitation systems from which you will have to choose: Jet Agitation and Paddle Agitation.

Pros & Cons of Jet Agitation Systems

Jet Agitation systems utilize a centrifugal pump for both mixing and spraying operations on the hydroseeding machine.  The pump must be run the entire time you are using the machine. A portion of the pump’s output is directed back into the tank through a series of jets to facilitate mixing of the mulch, seed, fertilizer, etc. that you will load into the tank. The remainder of the pump’s output is used to push the material through the hose so that it can be applied to the ground.  

Easy to Use & Low Cost of Ownership

Jet agitation systems are very easy to use because there are minimal moving parts or controls to contend with.  You simply put water in the tank and start the engine and the pump does the rest.  Because these systems are simple with few moving parts, Jet Agitation Hydroseeding Equipment is less expensive to own and operate than their Paddle Agitation counterparts.  

Limitations of Jet Agitation

There are some limitations to jet agitation systems, however.  Jet agitation machines were primarily designed to run paper fiber hydroseeding mulch. Paper mulch has a very short fiber length and quickly absorbs the maximum amount of water that it can handle.  This makes its performance in a jet agitation machine very predictable.

If you add the correct amount of mulch, you should have trouble-free operation.  Many job conditions demand other types of mulch that are much less predictable in jet agitation systems.  Wood fiber mulch is frequently specified on jobs where erosion is a serious concern or where temperature extremes and moisture availability are issues. Wood fiber mulch has a longer fiber length which in some cases can cause clogging in a jet agitation system.  Wood fiber mulch continues to absorb water and swell the longer it sits in the tank, which can also lead to clogging issues.  

Some jet agitation systems can handle mixtures of wood and paper mulch, but no jet agitation machine can regularly spray 100% wood fiber mulch unless the slurry is thinned down to a point where you might as well not have any mulch in the tank at all.  Jet Agitation Hydroseeding Equipment has its place in the industry, even with these limitations.  In many parts of the country, paper fiber mulch is the primary mulch used on residential and small commercial jobs and with the lower cost of ownership of Jet Agitation Hydroseeding Equipment, they are frequently the machine of choice for contractors that are just getting into the hydroseeding industry.

apex large hydroseeder with twin hydraulic paddle agitation

Benefits of Paddle Agitation Systems

Paddle agitation systems have a shaft that runs the length of the tank with steel paddles mounted on it.  The paddles are driven by belts and pulleys that are connected to the engine, or by a hydraulic system.  The big advantage to paddle agitation systems is their ability to mix any type of mulch.  Whether you are mixing paper mulch, wood fiber mulch, cotton fiber mulch, or BFM’s, a paddle agitation system can handle it.  

Designed to Spray & Mix Thick Slurries

In addition to the ability to spray any kind of mulch, paddle agitation systems can mix thicker slurries than jet agitation systems.  This means that for the same size machine, you can use more mulch in the tank and therefore you can spray more area per load.  The spray pump on machines with paddle agitation systems is used only to apply the materials to the ground, not to mix the slurry. While these machines are quite capable in terms of the products they can mix, they are also much more complex than Jet Agitation Hydroseeding Equipment.  

The Methods of Powering Paddles

There are two methods of powering the paddles on a paddle agitation system.  One method, frequently called mechanical paddle agitation, uses a combination of belts, pulleys, and a clutch to drive the paddles.  The other system is called hydraulic paddle agitation and it uses a hydraulic motor to drive the paddles.  There is a secondary drive system that powers the spray pump.  One of the following three methods for driving the spray pump can be found on various machines.  One method uses belts, pulleys and a clutch.  An alternate method is to direct drive the pump which also requires a clutch.  The third method is to hydraulically drive the spray pump.  As you might guess, the cost of ownership will be higher on a machine with a paddle agitation system.  In return for the increased cost, you get a machine with much greater capability.  You won’t have to turn down a job because your machine isn’t capable of mixing the mulch that is required. 

How Do You Choose the Right Hydroseeding Equipment for the Job?

When looking for a hydroseeding or hydromulching machine, you must consider the type of job you will be doing and what machine would be best suited for it. Not only should you consider the type of agitation system the machine uses, but also the load and landscape the machine is designed for. 

Here are our picks for the right hydroseeder for those just starting out, for mid-sized projects and for large-scale hydroseeding projects:

Easy Lawn’s Landscaper Series:

  • The Easy Lawn landscaper series consists of smaller capacity units ranging from 100 Gallon to 900 Gallon tanks designed to help you seed your next landscaping project as quickly and easily as possible. The 100-gallon tank easily fits in the back of a truck, and is perfect for the small-scale landscape contractor looking for professional performance. 
  • The jet agitation system in the Easy Lawn product line ensures fast mixing, trouble-free operation and easy cleaning. Even better, these machines operate at 35 psi even when maintaining full agitation. That’s enough pressure to push a slurry through 100 feet of a 1.5-inch hose. If you’re looking for affordable hydroseeding equipment with a punch, this is it.

Apex XA1200 Mid-Sized Hydroseeder:

  • The XA1200 is one of Apex Seeder’s best-selling units. This 1200-gallon paddle agitated unit is made for larger production sizes and all hydraulic mulches, and can easily be towed behind a one-ton pickup truck. This setup works wonders for medium to large-scale applications, capable of spraying distances of up to 185 feet, and comes with options for customization.

Apex XA3300/XA4000/XA5000 Large Commercial Hydroseeders:

  • Apex’s Large Hydroseeder Series is for large-scale projects and can be used to apply liquid-based materials to any location: commercial, residential, mining sites, landfills, golf courses, rail lines, oil/gas wells and lines. 
  • These hard-working machines can be used to mix and apply dust control palliative, all types of hydraulic mulches (wood and paper and blends), BFM (Bonded Fiber Matrix), ADC (Alternative Daily Cover), and all types of seeds, fertilizers and lime. The mixing system is engineered to quickly blend the thickest materials used in the industry with two variable speed and reversible hydraulically-driven agitators within the tank. Like all Apex Hydroseeders, the stainless steel tank provides years of corrosion-resistance. Most impressively, these hydroseeders can discharge a variety of materials at distances up to 325 feet (99 meters) without modification to the pump or adjusting the mixing instructions and are engineered to allow the complete emptying of the mixing tank.

What Else Should First-Time Hydroseeder Buyers Know?

One of the most important things to know when purchasing a hydroseeder is the type and size of landscape you will be dealing with. Understanding the type of landscape you will be handing determines the types of seeds and mulch you can use, while the size determines the size of your hydroseeding machine and how much material you need to buy beforehand.

Contact Apex Seeder

Get started on hydroseeding and hydromulching by checking out equipment for sale by Apex! Contact us today and we can help you determine which hydroseeding and hydromulching machine will best fit your needs.

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Doug Wysong

Doug has been designing innovative equipment for the erosion control industry for almost 40 years. With a degree in Agricultural Engineering, Doug specializes in power and energy systems, vehicle dynamics, and slurry pump technology to keep the Apex brand at the forefront of the landscaping industry. Doug has learned much from customers over the years and feels their input is vital in making the equipment he designs special. The best days are spent hydroseeding with customers and seeing what they can do with the product!