Soil science blog

10 qualities of an effective hydromulch solution

Soil science can make a substantial difference in the outcome of soil remediation projects, particularly when soil is depleted.

Using a high-quality hydromulch is essential for several reasons: it allows for natural soil hydration, reduces water usage and erosion risk, and optimises soil biology development processes.  

In contrast, using an ineffective hydromulch product can lead to problematic vegetation establishment patterns such as poor cover crop strike, signs of nutrient and mineral imbalances, and bare soil during establishment.  

Finding the right hydromulch comes down to knowing which key characteristics to look for. While other manufacturers of hydromulch media claim that higher water-holding capacity leads to better performance, we take a more holistic approach to maximising water penetration into the soil. 

Read on for a comprehensive review of the key qualities you should look for in a hydromulch medium. 

Ease of use

The EnviroStraw range has been carefully designed for ease of use, particularly our Australian-first all-in-one-bag hydromulch products. These come packed on heavy-duty pallets of 52 x 20 kg UV- and water-resistant bales wrapped in agriculture-grade pallet wrap. This ensures that the hydromulch is easy to transport, unload and move around the site upon delivery, reducing transport costs. Finally, the application is as simple as adding seed and spraying the slurry onto the earth. 

Mechanical and thermal processing

By mechanically processing the fibre, you get a more consistent end product with specific qualities, including desired fibre length. Thermal processing also improves water absorbency and ensures that the product is also free from pathogens and weed seeds.

Plant fibre diversity

Including a diversity of fibre improves slurry thickness, shear stress and ground coverage, which in turn improves overall performance. Different fibre lengths also encourage fibre entanglement and interlocking, which is critical to effective erosion control. EnviroStraw’s processing methods include up to 4 fibre sources and a varied range of fibre lengths, from 5mm to 25mm. It also encourages a diverse range of soil biology which is beneficial in soil conditioning and vegetation establishment. 

A balanced carbon-to-nitrogen ratio

All soil biology species need a range of nutrients, including carbon and nitrogen, in quantities determined by the climate and soil types in the region. While nitrogen drawdown hinders plant establishment, a balanced carbon-to-nitrogen ratio encourages healthy plant growth, minimising the effects of yellowing nutrient lock up and nitrogen draw down. All EnviroStraw Hydromulch products are balanced and independently tested to ensure that they meet the industry standard of below 50:1.

High water-to-mulch mix ratio

The correct mix of hydromulch fibres can significantly improve the volume of hydromulch that can be loaded into each tank. This in turn improves the coverage area and on-site efficiency which reduces the volume of water required to complete the project and the concentration of CO2 emissions released during truck movements on site. To assist clients and contractors in achieving these goals, EnviroStraw has created calculators for water use efficiency and coverage area per tank.  

Water-holding capacity

Water-absorbent Hydromulch acts like a sponge on the soil surface, hindering water penetration and increasing the quantity of water required to hydrate the soil beneath. Then, as this highly water-absorbent hydromulch layer dries out, it acts like a wick pulling up water from the soil below. This not only dries out the soil, but also hinders deep plant root penetration which is critical to effective erosion control and healthy drought-resistant plant growth.

In contrast, EnviroStraw Hydromulch products are designed to hold onto enough water to enhance soil microbiology activity, increase water penetration into the soil and encourage seed germination whilst minimising the wicking effect. This leads to deep root formation beyond the Hydromulch layer and topsoil, and ultimately more resilient grass coverage, even during extreme temperature fluctuations.

This new way of thinking about water-holding capacity in the EnviroStraw Hydromulch product range raises new insights into the process of growing healthy, drought-resistant plants in highly disturbed soils on revegetation projects.

Shoot distance and ground coverage

An effective hydromulch must be capable of covering the ground well and shooting long distances. This largely comes down to slurry thickness – if a Hydromulch slurry is too thin and watery, the mulch will separate from the water during the spraying process, reducing shoot distance and ground coverage. EnviroStraw Hydromulch products meet and exceed all machinery manufacturers’ specifications, ensuring that slurry thickness, fibre length, sprayability and shoot distance are all primed for maximum performance and efficiency.

Outstanding erosion control

Fast, effective germination allows the cover crop to absorb raindrop impact and control overland water flow, therefore minimising soil loss from a project site. EnviroStraw products have been independently tested to meet or exceed industry standards for erosion control with C-factor data as low as 0.001.

Diverse plant germination

Plant diversity across cover crops, pasture species and native plants is key to a thriving ecosystem. Native plants are particularly important as they typically thrive in the environment in which they are sown. They tend to grow deeper roots, leading to increased drought tolerance, reduced erosion and fewer ongoing maintenance requirements. For this reason, EnviroStraw  hydromulch products are designed to be native-plant friendly. The products include a suite of microbes specifically designed for disturbed soils as well as biostimulants and other inputs that build soil health and encourage the establishment of deep-rooted native plants. 


Hydromulch should be manufactured from renewable resources that are readily available that are not harmful to the environment. Read the EnviroStraw environmental policy.

Optimise your outcomes with EnviroStraw hydromulch

EnviroStraw’s hydromulch solutions are a key component of our revegetation product range. Designed with the optimum blend and length of fibres and ratio of carbon to nitrogen, our EnviroStraw range (HGM and BFM) and biotic growth media products (BFM Complete and EnviroMatrix ECM) give new growth every opportunity to thrive. Find out more about our selection of hydromulch products.

Back to News