What Is Spray-On Grass Seed (A.K.A. Hydroseeding)?

For most homeowners, starting or repairing a lawn means paying big bucks for professional sod or spreading dry seed by hand. Spray-on grass seed is an exciting alternative to these methods that could improve germination, reduce erosion, and save you money all at the same time!

What Is Spray-On Grass Seed?

Spray-on grass seed, a process commonly known as hydroseeding, is an alternative to popular lawn starting methods like sod and dry seed.

According to Bob Vila, hydroseeding has been used since the 1940s to spread grass seed over large slopes and other hard-to-reach areas. Recently, however, spray-on grass seed has gained traction in the world of residential lawn care.

As the name implies, hydroseeding involves a mixture of grass seed and water. But that’s not all you need for successful hydroseeding!

The typical spray-on grass seed contains the following components:

  • Grass seed
  • Water
  • Lawn fertilizer
  • Organic mulch
  • Bonding agents (to keep the above materials from separating)

In commercial applications, the ingredients are mixed together and sprayed over the soil using a high-powered hose. At-home spray-on grass seed can be applied with a standard garden hose.

Hydroseeding Vs. Hydromulching

Hydroseeding Vs. Hydromulching

When comparing different spray-on grass seed services and products, you might come across the term “hydromulching.” While these techniques are very similar, it’s important not to get the two confused with one another!

The key difference between hydroseeding and hydromulching is that the latter does not contain any grass seed. Instead, hydromulching is usually used for temporary erosion control in construction zones.

Spray-On Grass Seed Pros and Cons

There’s no denying that hydroseeding is a much cooler concept than laying down sod or hand-spreading dry grass seed. But what other benefits does this lawn-starting method have to offer? And what are the drawbacks of choosing spray-on grass seed for your own lawn?

Pros

  • Easy to apply — Hydroseeding is extremely easy to apply, even in areas where other methods would be difficult or impossible. Historically, spray-on grass seed has been used to cover large, inaccessible slopes.
  • Affordability — With the exception of traditional dry grass seed, hydroseeding is one of the most cost-effective options for filling in a lawn.
  • Better germination rate — The inclusion of fertilizer and mulch in most spray-on grass seed ensure that the seeds have everything they need to germinate and sprout. On average, hydroseeding produces faster results than dry seed.
  • Erosion control — Spray-on grass seed includes ingredients that prevent soil erosion while the seeds become established. Most hydroseeding formulas also help prevent weed growth.

Cons

  • Difficult to DIY — For all but the smallest lawns, hiring a hydroseeding professional is practically a must. (We’ll touch on the best DIY spray-on grass seed options in a moment.)
  • No instant gratification — Hydroseeding makes quick work of applying grass seed but it won’t do much to speed up your lawn’s actual growth rate. You should expect to stay off of treated areas for at least a month while the grass fills in.
  • Requires regular irrigation — For several weeks after hydroseeding, your lawn will require a significant amount of water. New spray-on grass seed must be watered up to 4 times per day during the first two weeks.

When To Consider Hydroseeding For Your Lawn

grass seed

Spray-on grass seed is most beneficial when used on large sections of bare soil. As a general rule, you should consider hydroseeding if you have over half of an acre in need of treatment.

You’ll often see spray-on grass seed used around newly built homes since the surrounding soil is completely bare.

Hydroseeding is the go-to strategy for reseeding steep slopes that would be difficult to cover with sod or traverse with a traditional seed spreader. These areas also tend to be the most at risk of erosion or run-off — spray-on grass seed may prevent such issues.

This method can also be used to spread more than just grass seed! You can use hydroseeding to distribute native plants throughout an empty field or reclaimed section of prairie.

Cost of Professional Hydroseeding

The best way to cover large sections of soil is by hiring a professional who offers hydroseeding.

As with any lawn care service, the cost of professional hydroseeding varies by location, property size, and project scope.

According to HomeAdvisor, the current average cost of hydroseeding is $3,500 per acre. This equates to less than $2,000 to treat the average yard in the United States.

These cost estimates don’t include the work needed to prepare the soil for hydroseeding. Doing some or all of the prep work yourself can greatly cut overall costs.

Alternatively, you can rent the equipment and apply the seed mixture yourself.

Renting the equipment for hydroseeding costs $500 per day on average. You’ll also need to budget for the grass seed mixture, energy consumption, and transportation for the rented machinery.

DIY Spray-On Grass Seed Review: Is It Worth It?

spray on grass

If you’re intrigued by the concept of hydroseeding but don’t want to shell out to hire a professional team or rent commercial equipment, there is one other option. But keep in mind that it offers just a fraction of the benefits you’d get from traditional hydroseeding.

Spray-on grass seed kits are available from many lawn and garden retailers. These kits typically include a handheld sprayer that connects to a standard garden hose.

The concept behind DIY spray-on grass seed is very similar to large-scale hydroseeding. You fill the handheld sprayer with a mixture of seed, fertilizer, and mulch. You then apply the mixture to bare soil.

Unfortunately, these DIY kits fall short of regular hydroseeding because they only cover a small section of soil at a time.

DIY spray-on grass seed is ideal for filling bare patches in an already established yard. Because of this restriction, however, these kits are no more convenient than spreading dry seeds or using small pieces of sod.

Best Spray-On Grass Seed For Homeowners

As long as you set realistic expectations — a DIY kit won’t deliver the same results as professional hydroseeding — spray-on grass seed can be a fun alternative to broadcasting seed by hand.

There are a few brands out there offering these types of kits. The most popular one, however, is the Hydro Mousse Liquid Lawn System.

Hydro Mousse Liquid Lawn System

Pros

  • Compatible with any standard garden hose
  • Clearly marks where you’ve sprayed
  • Refills available separately

Cons

  • Only covers a small area
  • Seed mixture is thinner than expected

This spray-on grass seed kit includes a handheld sprayer attachment and enough seed mixture to cover 100 square feet (or more if you’re overseeding a patchy lawn). In terms of grass species, you can currently choose from a High-Performance Blend or Bermuda Blend.

Refills are sold separately from the sprayer kit. Each refill covers up to 400 square feet when overseeding or 200 square feet when applied to bare soil.

The benefits of this spray-on grass seed system include being able to see where you’ve already sprayed and a lower risk of the seed blowing or washing away before it germinates.

While the idea behind this system is great in theory, you shouldn’t expect any better results than you’d see from dry grass seed. When you consider the price per square foot, there’s a good chance that your money would be better spent renting a commercial sprayer.

Getting The Best Results From Spray-On Grass Seed

watering grass-seed

The biggest mistake you can make when hydroseeding is to not prepare the soil beforehand. The second is to not maintain the area properly after the fact!

Following these steps will ensure you get the best results possible whether hiring a professional or doing the work yourself:

1. Remove All Weeds and Debris

Spray-on grass seed is not effective unless the target area is completely bare!

If you hydroseed over soil that is covered in weeds, rocks, or other debris, the seed will have a very hard time making contact with the earth. Even if you do see some germination, the end result will be a patchy, uneven lawn that needs further treatment.

Clearing the area you want to spray beforehand will ensure you get the best results possible no matter which hydroseeding method — professional or DIY — you choose.

2. Loosen and Amend the Soil

Once you’ve removed debris from the area, use a shovel or similar tool to break apart the top layer of soil. Dig several inches into the soil and remove any roots or large rocks you come across.

Now is also the perfect time to perform a soil test and amend the soil as needed.

Most native soil will benefit from the addition of organic matter (e.g., aged compost or manure). If the soil is particularly sandy or clay-heavy, you may wish to apply a new layer of topsoil.

3. Rake the Soil

To create a flat canvas for your new grass seed, use a metal rake to smooth out any hills and valleys in the soil.

If you’re seeding a large area that requires more intricate grading, it’s worth it to call in a professional for the best results possible.

Rake the Soil

4. Spray Grass Seed

Apply the seed mixture on a clear day with minimal wind.

While hydroseeding does reduce the risk of run-off, it won’t protect against heavy rain or flooding. So it’s also a good idea to check the forecast for the next few days.

5. Keep the Area Well-Watered

As a general rule, spray-on grass seed requires more water immediately after application than other types of grass seed.

For the first 2 weeks, water the area 2 to 4 times per day (adjusting for rain). Always water lightly to prevent water from collecting on the soil’s surface.

Once the grass starts to sprout, slowly reduce the watering frequency over several weeks.

6. Reduce Foot Traffic

Young grass cannot tolerate foot traffic the way mature grass can. This is especially true for spray-on grass seed.

Ideally, you should eliminate all foot traffic in the area for at least a month after hydroseeding. Foot traffic should be kept to a minimum until the grass is at least 3 months old.

home grass seed

Final Thoughts

Spray-on grass seed is the best option for a variety of applications. In particular, you should consider hydroseeding for any large, hard-to-reach areas that are in need of new turf!

It is not, however, a one-size-fits-all solution. For example, hydroseeding is no more convenient or cost-effective when it comes to repairing small patches of dead grass. And many DIY spray-on grass seed kits leave much to be desired when compared to professional services.

Knowing the right time to utilize this seeding method (and when you should pay for the help of a professional) is key to getting the best results in your own yard!