We are passionate about recycling at Coastal, and composting is recycling in its truest form. Currently, each year Coastal Organics gives over 22,000 tonnes of green garden waste a new purpose, by turning it into compost.

Every aspect of composting takes time and has a process that needs to be carefully monitored. We have broken it down to give you a better understanding of the journey Coastal Organics compost takes from on its journey from waste to resource.

What is the process to create compost?

Many people don’t realise that turning the garden waste of Devon into compost is a 12-week process, which involves rigorous testing to ensure that it is of the quality needed and in accordance with national composting standards (PAS100).

Our composting process follows these steps


After the garden waste arrives, it is passed through our shredder at Hill Barton and made into an elongated heap (windrow) so that we can track it through the 12-week cycle.


The material is stored in batches called windrows. The batches have to be large enough to generate heat so that the material can be sanitised as well as create the right conditions for microbial breakdown of the waste. Temperatures in the centre of the piles have been known to hit 70oC degrees. In order to aerate the material, the windrows are turned by machine every four weeks (i.e. three times over the 12-week cycle); thereby helping maintain the right conditions for composting.


At the final stage of the 12 week composting process, the material is screened through a fixed rotating trommel screener (with three different sized drums) that produces three different grades of compost: 10mm, 16mm & 50mm.

Finally, we routinely take samples of completed batches of compost to test for nutritional quality and to check that the relevant parameters are within the critical limits set by PAS100.


As a result of the above process, three grades of PAS100 compliant compost are created:

  • 10mm Grade – This is the cream of the crop and the finest of the three. It is predominately used as a top dressing on golf courses – providing them with that enviable green hue, it is also used in horticultural/glasshouse situations.
  • 16mm Grade – Our principle grade of compost and the most popular choice for many. It is commonly used by landscapers and farmers as a means of helping to provide organic matter and a ready source of nutrients for the soil.
  • 50mm – This grade of compost is a rough mulch-like material that provides added structure to the soil; also, the woody elements that remain in the compost mean that nutrients are released slowly, so it is ideal for use on farms.


The success of Coastal Organics

We are forecasting that we will be creating over 35,000 tonnes of compost that will benefit the entire community.

Since setting up our new home at Hill Barton, Coastal Organics has gone from strength to strength with local farmers reaping the rewards of using our currently free PAS 100 compost which provides:

  • Reduction in the need for expensive fertilisers
  • Reducing run off
  • Improving the workability of heavy soils
  • Increasing crop yield
  • Adding vital nutrients to soil

We value the importance of composting as part of our sustainable waste management approach encouraging landfill diversion. Providing a green product that can be applied to a number of end uses from large farms, landscapers and small community allotment societies to improve the condition of their soil.

Lyn Chadwick, Manager, Coastal Organics