Compost Use in Horticulture

Compost lends itself very well to horticulture, used either as a growing media constituent or "neat" as a soil improver. In fact, many Growing Media manufacturers are using compost as part of their peat replacement programmes as they transition to more sustainable growing media. 

The Growing Media Initiative (GMI) is a scheme developed by the Horticultural Trades Association in conjunction with the Growing Media Association, DIY and Garden Centre retailers, Defra, the RSPB and the Royal Horticultural Society. 

It aims to help the horticultural industry in the UK meet government targets for reduction in peat use and compost is playing an important role in helping organisations achieve this.

Positive progress continues to be made towards the development of a new Responsible Sourcing scheme to replace the existing GMI scheme. A pilot scheme launched in 2016, and is ongoing.

What are the benefits?

It’s not just the environmental features of compost that make it worth considering. Whether you're a horticulturist, grower or growing media manufacturer, compost’s benefits can translate into improved plant establishment, growth and survival, leading to significant cost savings.

These benefits include:

  • Reduced need for fertilisers as compost contains Nitrogen, Phosphate and Potassium.
  • Compost may assist in the suppression of some plant diseases because it is more biologically active than other media constituents. It is thought that the populations of micro-organisms present in some composts, may act to cause suppression of soil borne plant pathogens, and this may be through a combination of factors such as competition, antibiosis, parasitism, and induced systemic resistance in plants.
  • Contains all the main plant micro nutrients such as Sulphur and Iron.
  • Contains organic matter for good soil/media structure.
  • Reduced need for liming.

WRAP’s Resources

All of the compost suppliers on the BSI PAS 100 scheme (REAL's Certification Scheme for quality composts) can supply recent laboratory data e.g. total and available Nitrogen to help you successfully use their product.

Find out more information about using compost in growing media:

De-mystifying the use of PAS 100 compost in horticultural growing media >>
Compost production for use in growing media >>
Guidelines for the specification of quality compost for use in growing media >>
Case study – Jack Moody >>
Case study – compost play Royal role at Duchy of Cornwall Nursery >>

Where next?

Want to know more about composting? Take a look at our reports, guides, tools and case studies for further information:

Reports >>
Guides >>
Tools >>
Case studies >>