Organic Waste Management at Kew Garden, London

A talk on compost and waste management by David Barnes, the Manager of Horticultural Support at Kew garden. This is part of fielding Module and its suppose to help me to understand how certain things (wildlife, waste, ect) can be managed.

Kew Garden produces over 100 tonnes of waste plant materials every week. As part of Kew’s commitment to practise sustainable horticulture, they recycle 99% of their organic waste. The method used to manage the organic waste is known as Composting.

Composting at Kew:

Composting organic waste is more environmentally friendly than throwing all the waste in a land fill site.

It’s Advantages:

• Compost adds more nutrients to the soil, to reduce the use of artificial fertilizers


• Improves the soils structure so plants grows better and healthy, therefore making them resistant to pest and diseases


• Compost can be used as mulch on soil surfaces to help retain water


• Helps to reduce the amount of weeds present

How compost is made?

The sorted materials such as herbaceous and woody trees and shrubs from felled tree branches, etc heaped

• The woody trees and shrubs from felled tree branches materials are screened and shredded into wood chips

From: Chunks of timber

To: Wood Chips

• Herbaceous plant materials (leaves & grass clipping) are only shredding.
  
  

Heap of leaves and grass clippings

The wood chips are mixed on a ratio of 4:1 with the fresh stable manure, while the shredder herbaceous material is mixed on an equal ratio to the manure.

The mixed shredded materials are stored in heaps as shown below:

Herbaceous plant mixed with manure left to compost

Wood chip mixed with manure left to compost

These heaps are watered with stored rain water and turned regularly to maintain a low temperature. David Barnes said sometimes the temperature of the heaps can rise up to 850C that is high enough to set itself ablaze but the best temperature for the compost process is at 55oC. Therefore allowing micro-organism (bacteria and fungi) to break down the plant materials. The compost process takes about 10 – 12 weeks before it’s been taken back to the garden to be reused as mulch

In conclusion, I believe the waste management at Kew is very effective even though the scheme only started 10 years ago. It’s also very sustainable. It must have saved Kew gardens a lot of millions of pounds. Practising this self-effective method has been beneficial and encouraging to the public. Waste is not easy or simple to control and manage especially in Kew garden when they tend to have a huge number of visitors visiting a year.

The part I find very interesting is the fact that the composting heaps can generate a huge amount of energy on it’s own which is very good but now I’m also questioning why can’t this energy that is been produced be used to generate electricity (thermal energy) or something productive for the garden?

I have learnt so much about waste management and I’m planning to incorporate the method and processes into the management plan report on woodlands.