Every year, around early spring, we hear questions about spray on grass seed. Many people seem to have the same questions: What is hydroseeding? Should I try Hydro Mousse? Is “hydroseeding” better than sod? And, most of all, is spray-on grass seen worth the money?
Spray-On Grass Seed Explained
If you are a traditional lawn owner you may have never seen spray-on grass seed, or perhaps you thought it was only done by professionals. That’s not the case.
Spray-on grass seed, often known as “hydroseeding” is the process of spreading grass seed using a pre-mixed liquid. It’s like spray painting your lawn but instead of paint it’s a mixture of:
- (mostly) water
- grass seed
- bonding agent
This mixture is similar to spray-on lawn fertilizer, but it has grass seeds added. Grass seed is quite small so the water pressure available through a garden hose is enough to spread the mixture, through your range is limited. Professionals have bigger pumps, and bigger hoses, so they get the job done faster.
The pressure of the hose can give the grass seed some penetration into the soil, giving the grass a better chance early in life. Most of us have had expensive grass seed fail enough times that we want an edge we can get. Birds also don’t like the mulch component of the spray-on seed so this helps give your baby grass a chance.
Spray on grass seed is generally more expensive than applying grass seed alone, but considering that it requires on special tools (like a lawn cast spreader) and it includes the fertilizer, the price isn’t unreasonable.
Types of Spray-On Grass Seed
While the concept of spray-on seed is pretty simple, this isn’t something you make yourself. You’ll want to buy the pre-mixed hydroseed and then add water to create your own slurry at home.
Hydro Mousse Liquid Lawn
A popular option for spray-on grass seed is Hydro Mousse. This is a do-it-yourself spray grass seed that sells for about $25 and covers only 100 square feet. It uses a mixture of types of grass, making it versatile enough for many areas. It uses:
- 60% Tall Fescue Grass
- 20% Shining Star Perennial Ryegrass
- 10% Boreal Creeping Red Fescue Grass
- 10% Shamrock Kentucky Bluegrass
Hydro Mousse is widely available but 25 cents per square foot is quite expensive. This is a solution for spot fixes, for instance when you have a bulldozer or similar piece of machinery that has torn tracks in your lawn. You can walk along the ripped up strip of lawn, spraying as you go, and expect to see new grass in a few days.
Meanwhile, when spraying the Hydro Mousse you can use its “heavy seed mode” in which the spray will turn a dark green color which will color the dirt patches and make it quite clear which areas have been seeded and which have not.
Hydro Mousse is sold in 2lb. refills which don’t include the spray canister, so you can buy them and save some money with additional applications.
Hydro Mousse Alternatives
You might be surprised to learn that there aren’t that many alternatives to Hydro Mousse. Most spray-on grass seed jobs are large enough that people trust this work to professionals.
Hydro Mousse has a number a negative reviews online from people who have seen their TV ads and haven’t found the same success they were told to expect. This leads people to look for alternatives, but not many exist. At one time there was Hydro Shot and Gavin’s 3-in-1 Hydroseeder, but those products aren’t widely available any longer.
If you are of the DIY nature and you have a lot of ground to cover, you can rent a hydroseeder, buy or make hydroseed slurry, and attempt to spray grass seed on your own lawn. Having never attempted this, it’s not something we’d recommend, but many rental places offer hydroseeders, like the Finn T-30 or T-60 hydroseeders, which can handle up to 500 gallons of grass slurry. Just keep in mind that these are large, serious machines, not something you’d want to casually attempt without some research.
If you go this route you’ll need to make your own grass slurry, usually using some combination of:
- EZ Jet Spray Hydraulic Mulch
- Grass seed
- Tackifier (to keep the seed and mulch in place)
- Bio-Stimulants (natural fertilizers to help the seeds germinate)
- Dye (so you know where you’ve sprayed)
Some people add other things to their mixtures in order to make it more effective. Everyone has their own secret formula for the optimum performance in their area. Optional additions include:
- Liquid lime
- Co-Polymer Gel (to prevent water loss from the soil
- Spray-on Topsoil (like ProGanics)
There are a number of spray-on grass services in almost all localities. You can find a local vendor by searching for “spray-on grass near me” online or you can look for a national vendor. On the national side, the company best known for hydroseed services is TruGreen.
Cost of Hydroseeding
The price of hydroseeding a lawn will vary based on your area and the amount of coverage you need. Typical price estimates will be from $500 to $5000.
Prices will often be based on square footage of your lawn with prices averaging about 10 to 12 cents ($0.10 to 0.15) per square foot. This price is inclusive of materials and labor.
Some vendors will have grades of grass and/or grades of fertilizer that they use when spraying with prices at $0.10 on the low and and $0.20 on the high-end for premium grass spray slurry.
There can be other charges as well when you are paying a professional to do your spray-on seed. For example there will usually be an additional charge if your grass is on a slope, with small slopes having about a $0.04 surcharge and steep slopes going to $0.08. This is the case because hills require more materials, more expertise, and more control of the large spraying machines.
Is Spray-On Grass Seed Good?
As with some many things, the effectiveness of spray-on grass seed comes down to the execution. If you have a qualified professional who does a good job with the grass seed application you should have a great experience with spray-on seed, better growth and coverage than dry seeding, and for a fraction of the price of sod.
Spray-on grass seed in small applications, like the Hydro Mousse, is OK in a pinch but isn’t not as effective as it looks on TV and you can’t just spray and forget it. No matter how it’s applied, grass seedlings are sensitive to temperature and dryness, so you need to water and care for them diligently.
Spray-On Grass Seed Tips
- Always wear gloves when apply spray-on grass seed and avoid contact with skin and clothing
- As with any grass seed, make sure you adhere to the best timing for your seeds. In the fall, this means don’t put them down if you expect frost in the next 45 days. March through October is best for most of the US.
- Seeds can take up to 2 weeks to germinate, so don’t despair if you don’t see seedlings immediately
- Follow the watering instructions closely. You will generally want to water your lawn 2-3x a day for the initial period.
- Hydroseeding works best on freshly tilled soil. You can use it on patches, you’ll have mixed success relatively to tilled earth.
- Will rain wash spray-on grass seeds away?
No, a typical rain storm my wash away some of the green coloring that comes with your hydroseed but it shouldn't displace the grass seeds. If you get an exceptionally heavy storm right after hydroseeding and you have an erosion-prone lawn there may be some issues, but this is typically not a concern.
- Do birds eat spray-on grass seed?
While it's always difficult to keep birds away from seeds, generally birds will keep away from hydroseed because the mulch component of the spray-on seed is not something they want to eat. Hydroseed, especially when professionally applied, is driven into the soil as opposed to sitting on top of it, which also discourages birds.
- Can you use spray-on grass seed on a hill?
Spray-on grass seed will work on a hill but you should avoid putting it on extremely steep slopes as it can cause run-off and clumping of your seeds lower down the hill than you'd like.
- Is spray-on grass seed cheaper than sod?
Yes, sod will typically cost $0.33 to $0.50 a square foot where professionally applied hydroseed will cost about $0.10 to $0.15 per square foot. Of course sod will give you a full lawn immediately after it's laid where spray-on grass will need a least a month before it's mowed for the first time.