Peat compost has been sold in garden centres and used in glasshouses since the 1960s. It’s favoured due to its ability to improve soil structure, retain water and allow air circulation. The extraction of peat for horticulture has lead to the extensive degradation of peatlands, vital carbon stores created over thousands of years. If we are to reach net zero in the horticulture sector, we must move away from using peat products.

Sustainable alternatives to peat exist but supplies are either expensive or not available in sufficient quantities. For some applications, peat can be replaced with a single sustainable growing medium. For many applications however, a blend of raw materials is necessary to meet production cost and product quality criteria.

Our goal is to rapidly accelerate the development of new, reliable, and high performing peat alternative growing media. ADAS Horticulture are the only laboratory currently offering a growing media analysis and design service.

Contact details

Performance analysis

Extensive research has identified three key physical properties as indicators of growing media performance:

  1. Available water (AW) or water holding capacity,
  2. Bulk density (Db)
  3. Air-filled porosity (AFP) – sufficient pore space for plant roots to remain aerated, but not to the extent that the plant is drought stressed.

ADAS developed a Standard Operating Procedure for measuring these indicators in growing media samples.

Our analysis services

We can provide standard analysis of growing media raw material for AW, Db and AFP. This includes a client report.

In addition to standard analysis, we can also assess samples for Cation Exchange Capacity (bases that a medium can absorb per unit weight). Please not the minimum batch size is eight.

Blend Design

Our growing media blend design recommendations are produced using the ADAS Growing Media predictive model. The model has been designed to identify high performing mixes of raw materials from physical properties.  It avoids the need for the time consuming and expensive traditional, inherently variable plant testing. It does not, however, remove the need for “try before you buy” by the end-user.

Designed growing media may require both experimental and pre-commercial testing before full commercial use (see the Trial section below).

Our modelling services:

Mathematical modelling and statistics

  • Physical property interpretation, including dialogue and report
  • Blend prediction for target crop, including dialogue, report and software distributed under licence
  • Experimental design, including expert design and analysis input


Experimental testing of new growing media blends

At ADAS, we host multi-option irrigation and nutrient delivery system trials. These can be modified to accommodate any plant type, from bedding through to young trees. Fine-tuning growing media mixes to meet with target growing system type (e.g. drip, overhead sprinkler, subsurface irrigation, CRF / liquid feeding nutrition and so on) will require live crop testing.

We can provide expert statistical design and analysis which will help you get the most from such tests.

Our trial services:

  • Experimental testing, including 1 x experimental trial and report
  • Commercial testing, including 1 x commercial trial (size, location, interaction with nursery staff and number of crop growth stages dependent)

We are experts at on-site large scale implementation of commercial trials and we will work closely with clients to best meet their needs.

Service requests and processing times

Please contact Jill England to enquire about any of our services.

Any of the above services can be chosen in any combination to meet client needs.  Price will be given on application as experimental or commercial trial work pricing will be dependent on location, duration and complexity.

Turnaround time for physical properties and Cation Exchange Capacity, is six weeks from day of receipt. Any experimental design and modelling inputs will also be shared within that timeframe.

All materials are analysed in triplicate.

New project enquiries

We are open to new project work, industry workshop delivery or training to deploy our specialist growing media and crop system skills and knowledge. Please contact Jill England to enquire about any of our services.