Comparing Hydromulch: Standard Vs Ameliorated

Published by Paul Clarke on

Are you trying to choose between standard and ameliorated hydromulch? Here are the differences between them. Keep reading to find out what ingredients are used in each application and how they will benefit your site.

ameliorated hydromulch

Standard vs Ameliorated Hydromulch

Revegetation projects can range in size, anywhere from 100 sq.m up to 1,000,000 sq.m. When you add up the costs of a hydromulch application ranging from $0.25 to $6.50 per square metre, you want to be sure you’re spending your money on the right application for your site. 

You might be after the cheapest price, or you might have had failed applications in the past and need some advice on what to do for your site. After 40 years in the industry, one of the main questions we get asked is, ‘which is better? Standard Hydromulch or an Ameliorated Application?’. Well, the answer lies in the ingredients used and how they work to encourage grass growth and stabilise the soil on your site. If you choose the wrong application for your site you can end up paying more in rectification costs to achieve practical completion.

Which Should I Choose?

So, what does it come down to, cost or final result? For most people, the cheapest price is usually what they go for but take a moment to stop and think about what you’re paying for. Our tried and tested methods have proved time and time again that choosing the best mix for your site (not just the cheapest) is what is key to achieving the results you desire. 

Regardless of whether you’re starting to research hydromulch or you’ve worked in the industry for a couple of years, trying to figure out which application you need for your site doesn’t have to take up a lot of your time. In this article, I’m going to break down the differences between a standard and ameliorated application. Keep reading to find out what ingredients are used in each application, how they will benefit your site, and which choice is best for you.

What is a standard hydromulch application?

standard application

Standard Hydromulch is a safe, non-toxic method of growing grass and is the most common application used on civil construction sites. It is hydraulically applied out of a cannon or hand-held hose, depending on access restrictions.

Standard Hydromulch contains the following ingredients:

  • Seed
  • Water
  • Organic Fertiliser
  • Cellulose Fibre (e.g. Wood-fibre)
  • Polymer Binder

Pros of Standard Hydromulch

Standard Hydromulch applications are suitable for a range of different terrains, varying from flat surfaces to slopes. They can prevent erosion from heavy rainfall, mining, construction or infrastructure works. This is done by protecting the soil until vegetation grows and stabilises it. These applications are generally considered the cheaper or standard option of revegetation.

Cons of Standard Hydromulch

The limitation of the application is that it only includes minimal fertilisers and no ameliorants in the mix, so it may struggle to continue germination in the long term.

Cost of Standard Hydromulch

Applications start as little as $0.40 – $0.80 per square metre. Check out our Pricing Page for a rough price on your project.

Who is a Standard Hydromulch a good fit for?

If you have good quality topsoil and are looking for erosion control and dust suppression rather than long-term growth, then a standard hydromulch application may be the right fit for you.

What if I need to address defect rectification on my site?

failed application

Reasons why your application may have failed in the past are likely a result of the application not being tailored to the site conditions. 

Not all applications are the same as different companies prefer to use their own or certain suppliers’ specific materials.

Different materials result in varying levels of mix suitability for your site. Soil testing is the key here. It removes the guess-work and tells you exactly what the soil needs to make the grass grow. The application can then be tailored to suit these results.

This is called an ameliorated hydromulch application. It is more likely to have the additives necessary to improve the health of the soil and create suitable nutrient levels for the grass to germinate.

What is an Ameliorated Application?

ameliorated application grass growth berrima

An ameliorated application is like standard hydromulch, except it has extra additives. These change the properties of the soil, improving the microbiology and providing the nutrition necessary for long term grass growth. For instance, fertilisers can be added to the mix to overcome mineral nutrient deficiencies. 

Depending on your site requirements, you might benefit from using an ameliorated application like a compost blanket. A compost blanket consists of:

  •         Seed
  •         Water
  •         Organic Fertiliser
  •         Inorganic Fertiliser
  •         Wood Fibre
  •         Polymer Binder
  •         And Ameliorants (Lime, Gypsum & Compost)

Pros of an Ameliorated Compost Blanket Application 

Compost Blankets provide the nutrients required for long-term grass coverage.

The materials and quantities used in the compost blankets derive from testing the soil and then designing the appropriate mix to suit. This allows for the best chance for successful results to occur.

About 70-80% of germination is achieved in four to six weeks, depending on climatic conditions and the rainfall received. 

Unless in extended dry periods, the application does not require any maintenance watering. Check out this video for more information.

Cons of an Ameliorated Application 

More expensive initially, but saves you money not having to do re-works. Doing it right, the first time, saves money on repeated applications if poor results are achieved with unsuitable applications.

Cost of an Ameliorated Application 

Compost Blankets vary from $0.80 – $5.00 per square metre, pending soil amelioration requirements (determined by a soil analysis). Check out our Pricing Page for a rough price on your project.

Who is an Ameliorated Application a good fit for?

  • You have used hydromulch applications in the past, but they have failed to germinate.
  • Your soil is of poor quality, or you have no topsoil. 
  • You require defects rectification.
  • If you’re starting a new project, compost blankets can help you set the stage for successful grass growth.
  • Projects requiring sustainable long-term growth and little to no maintenance watering costs.
  • If you need to address erosion control problems on your site. 
  • Like standard applications, compost blankets also incorporate wood fibre and polymer binder into their mix. Together with the added ameliorants, this forms a protective layer on the soil surface, holding the seed in place. Allowing for the application to remain intact in heavy rain, with ingredients washing into the surface rather than running off into the drain.

Case Studies: Ameliorated Hydromulch in Practise

Parkes to Narromine


The Inland Rail – Parkes to Narromine (P2N) project presented the problem of large-scale open areas, requiring fast applications and effective germination in poor quality topsoil along some 103 kms of the rail corridor. The specifications for revegetation required an appropriate methodology to ensure an appropriate outcome was achieved, and reworks were not undertaken or required. 

The ability to ameliorate the soils in situ, along with covering large areas in a short time frame led to delivering a successful result, and client handover.

Oxley Highway

ameliorated application

The Pacific Highway – Oxley Highway to Kundabung upgrade presented a variety of potential issues during the revegetation of the site. Valley Hydramulch & Revegetation was required to develop a solution to failing standard applications on site. A mix was developed and tailored to the site soil conditions. This application would provide successful growth on site soils even in heavy rain and with poor surface preparation.

Is Standard or Ameliorated Hydromulch Right for You?

Keep in mind, that your final choice will be based on your budget, the constraints of your project, specification and finish required. We always recommend soil testing and follow the intent of the RMS R178 Specification (the industry standard).

After 40 years of experience, the best advice we can give you is to choose a supplier with a good track record and proven results. As well as being able to communicate with you about what mix will work best for the site to achieve the results you’re after for practical completion without costly re-works. Remember that the key differences between applications lie in the ingredients used, which have a big impact on the effectiveness of the application. These ingredients also affect the success of the long-term growth on your site.

Depending on your site’s needs, you are now well equipped with enough information to decide on whether you require a standard or ameliorated application. If you’re still not sure what application you need, book a meeting with one of our friendly team members, and they will be happy to chat with you. Otherwise, if you’re ready to get a price, fill out a quote form on our website.