Home / Services / Hydromulching



Hydromulching is a one step method of undertaking revegetation. Hydromulching is similar to Hydroseeding, but it includes the additional and important ingredient of mulch to the mix.

The mulch acts as a cover for the seed to help retain moisture around the seed for even germination and growth, and to shield the bare ground from the impact of raindrops until the vegetative cover is established.

The hydromulching mix consists of a slurry of water, seed, fertiliser and a mulch material agitated and kept in suspension until the operator is ready to spray the mix onto the work area.

GRASSMASTER has a broad range of equipment and long hoses, so we can treat areas with difficult access

There are four main components of a good hydromulching mix, apart from the water, which is simply used to transport the mixture.

1. The main components are:
2. Seed Selection
3. Mulch Selection
4. Fertiliser Selection
5. Binder Selection

a) Seed Selection

There’s always a “best” seed or seed mix for every project and it’s very important that the selection is made carefully. Several factors should be considered when selecting the seed.

Climatic Conditions

1. Seasonal Conditions
2. Project Goals
3. Soil Type
4. Availability of Irrigation

b) Mulch Selection

The purpose of the mulch in the hydromulching process is to act as a cover for the seed, and to help retain moisture around the seed which is important for even germination and growth. The mulch also shields the bare ground against the impact of raindrops until the vegetative cover is established.

The mulch material also links the soil particles together and helps prevent them from being dislodged by wind and stormwater. A good mix of fibre lengths helps to form a cohesive matrix, while allowing the soil to breathe. Therrno-mechanically (heat treated) refined wood fibre is accepted world wide as the best mulch available. The wood fibre mulch chosen should be a specially manufactured product for this purpose. By-products and newspaper should be “avoided”.

A good quality wood mulch such as Eco-Fibre® will retain up to twelve times its own weight in water. This water is readily available to the seed to help germination.

c) Fertiliser Selection

Where possible the choice of fertiliser should be based on soil analysis from the actual site. The two chemical components, Potassium and Phosphate are the most important to plant growth and in particular for the formation of a healthy root system. High nitrogen fertilisers are not necessarily the best choice as nitrogen can retard germination. The ideal fertiliser should be a slow release type supplying Nitrogen, Phosphate, Potassium and Micro-nutrients to help the plant attain good root growth and healthy foliage.

d) Binder Selection

Prior to germination of the plants, the soil is very susceptible to erosion by wind and water. The addition of a tackifier to the hydromulch mix will adhere the wood fibre to the soil surface much more readily, and help with even germination of the plants. The additional cost can be economically justified in severe areas by producing a better end result.