Compost Heap 

Kew’s compost heap is one of the biggest non-commercial heaps in Europe.

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Gardeners digging at the Compost Heap

Compost Heap

Did you know?

  • Kew makes 4,000 cubic metres of mulch a year. Because it doesn’t have to buy in mulch or take waste to landfill sites, this saves around £500,000 a year.
  • In 2005 Kew became the first World Heritage Site to gain the ISO14001 accreditation for sustainability.

The compost heap viewing platform

Kew’s compost heap lies south of the Lake in an area called the Stable Yard. This is off-limits to visitors but there is a viewing platform in the Pinetum from where the compost-making process can be observed. All garden waste is taken to the yard and placed on one of two huge mounds, one containing woody material and the other herbaceous cuttings. Both piles are screened, shredded and mixed with generous helpings of manure from the Royal Horse Artillery Stables in St John's Wood.

The decomposing material heats up naturally to 60 °C and rapidly rots down. Staff occasionally sprinkle it with water and turn it by JCB but no other action is required. Eight weeks after arriving in the yard it is ready to go back on the garden as mulch or to enrich the plants it came from. Kew’s production of mulch contributes towards maintaining its ISO 14001 accreditation. This is a standard for sustainability, and covers areas of Kew’s operations such as water use, recycling and carbon emissions.


Peat-free compost at Kew

Peat bogs are important habitats and valuable stores of the greenhouse gas carbon dioxide. However the use of peat, primarily as a potting compost, has damaged or destroyed 94% of the the UK’s peat bogs. Kew took the decision to stop using peat in 1989, except for carnivorous plants that cannot be grown in any other medium. It now uses peat substitute for potting composts and makes home-grown mulches at Kew and Wakehurst Place, using waste plant matter from the Gardens.

Things to look out for

  • Kew’s resident peacocks seem to like the warmth of the compost heaps and can often be seen perched on top of them. 

5 comments on 'Compost Heap '


08/06/2013 7:00:43 PM | Report abuse

Mr Lynch reports Methane as NH4. I suspect he means CH4. Cheers Bob

Michael Lunch says

01/03/2011 8:40:57 PM | Report abuse

Intact peat bogs release Methane (NH4) which like CO2 is a greenhouse gas. In fact NH4 is 20 times as potent as CO2 as a greenhouse gas. However peat bogs are a significant place for biodiversity, can control flooding and also filters water. The question is how do we manage our peat bogs for the future? Biodiversity or greenhouse gases?


25/05/2010 12:00:00 AM | Report abuse

So pleased you put this on the site supports completely what we are doing here in Fermanagh producing peat free organic compost from stable manure and offering horse owners a waste management solution!! Lady Muck


01/04/2010 12:00:00 AM | Report abuse

What a great use of rubbish. There should be more. D. Northants


03/03/2010 12:00:00 AM | Report abuse

Like the picture; wish there were more. -Dean- Los Angeles, CA

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