Composting Events and news

4. Jun, 2020


There is still time to take part in  UCLs nationwide citizen science research experiment in compostable and biodegradable plastic and to help shape the future of the planet

UCL  would like you to help investigate the role and effectiveness of biodegradable and compostable packaging.  The survey is well underway but there is still time to take part. The first part of the experiment is a short  5 minute survey: UCL would like to know what you think of biodegradable plastics, what you do with them, and if you ever compost them yourself.

 The second part is optional for those who compost. It’s a home composting experiment. In which you are  asked to place a few biodegradable plastic items in your compost under controlled conditions, and then report back about whether they compost or not.

By taking part in the experiment, you will be helping to determine the viability of biodegradable and compostable plastics. The data collected from you will feed into a Live Composting Map, a live map of home composting activities across the UK, and, with your consent, you  will kept up-to-date with the project as it develops. However, you also have the option to remain anonymous.
This is one of a series of research initiatives currently being undertaken as part of UCL’s Plastic Waste Innovation Hub, jointly funded by UK Research and Innovation (UKRI) and the Engineering and Physical Sciences Research Council (EPSRC)

For more details go to

2. Jun, 2020

This spring it has been very dry in the UK  which presents an interesting situation when community composting on the allotment, a shortage of “Greens”.

Composting requires  a balanced  mix nitrogen rich “Greens” and carbon rich “Browns” and at home with materials available from the garden, kitchen  and packaging this does not present a problem. However, on the allotment the situation may be more challenging.

Greens  are usually green in colour, hence the name,  or are from plants that were green at some point and include fresh weeds,  leaves, and vegetables tops, plants  that have bolted and  fresh grass clippings, if available (many allotments no longer have grass paths).

Browns are usually brown in colour, or naturally turn brow. They are carbon-rich materials that help to add bulk to the material  assisting   air to filter through the bin. Brown materials include woody  plant material and dried leaves, dried grass clippings, hay , straw  and cardboard. Some Browns may have started life as greens but as they have aged  or dried out, they lose nitrogen and turn brown at the same time. Green leaves will have had a  high level of nitrogen when fresh, but as they dry and go  brown(ish) the nitrogen levels drop.

As can be seen from the photos much of the material left in the Reception bin this week consists of dried grass, dried weeds, and plants. If the  compost bin gets too dry the decomposing process will slow as the microbes will not be able to function effectively. As mention in the last blog there is a need to maintain the moisture level by watering the heap as fresh material is added.

But there is still a need to find and add Greens. Luckily, the answer can be found in the manure heap or chicken house.

In recent years, the use of manures in making compost has be criticized because of the perceived risks to health and concern that pathogens in the manure might infect the composter and contaminate  the  vegetables grown where the compost has been used. In fact, the risks are easily kept at an acceptable level and  benefits of using matured cow manure far outweigh  the risks particularly when there is a shortage of greens. Most allotments will have an arrangement with a local farmer to deliver cow manure and it is a good idea to keep a separate pile on the plot so that it matures.  Chicken manure is good if birds are kept on the plot.

When using manure in a pallet bin where the organic material has dried out,  I use  woody browns as the  base layer followed by the dried organic material, without trying to separate it into greens and browns. This is followed by a thin layer of manure. Each layer is patted down and ensure that it is level. The alternate garden waste and manure layers  are continued until the bin is full. It is then topped off with a 1 – 2-inch layer of completed compost  or garden soil.

23. May, 2020

This note supplements  the page on Moisture levels at       link Compost Moisture

When the moisture level of the composting materials fall below 40% decomposition will start to slow down and will virtually stop below 15%. During hot dry spells it is worth checking the moisture level and adding more water if required.

  The use of a “corkscrew” type aerator Compost Aeration during composting will enable a sample of material to be removed from the centre and lower levels of the bin or heap to provide a sample for moisture checks.  A handful of the compost is removed from the aerator  and  squeezed.  The  compost should have the consistency and moisture content of a wrung-out sponge.

Alternatively,  the sample can be tested using a moisture meter or a probe moisture meter can be inserted into the core of the bin from above or the through the side of the bin

 In the UK water can be added to the heap. I tend to “open” it up using a garden fork so that the water penetrates the material rather than run off.

 In hot climates where the sun or high environmental temperature is causing the compost to dry out there are a number of options, in addition to adding greens and waste, these include composting in a pit, rather than a bin in full sunlight, and keeping the compost covered, so as to reduce water loss by evaporation.

19. May, 2020

On package labels and symbols are designed to provide information on the source and disposal of the packaging that  is quickly and easily understood. In most cases this objective is achieved without further explanation,  but this is not always the case. There is considerable confusion over the meaning of the Green Dot  which does not mean that the packaging is recycled or recyclable but that the producer has contributed (financial?) to the recovery and recycling of packaging.

Degradable and biodegradable also cause some confusion Degradable means the entire product or package will completely break down and return to nature within a  “reasonably short period of time after customary disposal. The American Society for Testing and Materials (ASTM) defines biodegradables as: Anything that undergoes degradation resulting from the action of naturally occurring microorganisms such as bacteria, fungi, and algae  within a reasonably short period of time after customary disposal”, as indicated by reliable scientific evidence.

The “reasonably short period of time” for complete decomposition of solid waste products varies the US FTC suggest  one year while in the UK the test period is six months. Items destined for landfill, incinerator, or recycling facilities will not degrade within a year, so unqualified biodegradable claims for them should not be made. These terms can be potentially confusing to the public both in terms of where to dispose of the material  and what happens to it once discarded.

Compostable symbols also cause some confusion. The seedling and compostable designates that the package is suitable for only in an  industrial system. Where material can be home composted will have the term “home composting” on the pack.   Carry on Composting have prepared two free Power Point presentations covering over 40 on pack symbols that can be downloaded and used for training  and increasing awareness of the symbols they can be downloaded at or by using this link Compostable Bags 

15. May, 2020

Now that the lockdown has be lifted enough to allow travelling to the Compost Demonstration site to maintain the bins, we have the  challenge to clearing at least one of the Reception bins quickly to make room for fresh material from the allotments. During the past few weeks local  allotment plot holders have been able to work their plots as part of their exercise regime and as a consequence both reception bins have been filled.

Just before lockdown it was noticed that as result of the spring weeding prior to sowing and planting we were getting a high percentage of weeds for composting and unusually the soil had not been knocked off  the roots.  Luckily over the three of four weeks in the reception bins few had started to grow which will mean that we will be adding more soil to our bins than usual., as there will not be time to knock the soil from the plants when adding them to the bins. The lockdown also meant the main community pallet bins containing the compost made last year have not been emptied so the “household” bins on display will be used initial

Yesterday I started with two of our wooden bins a Lacewing    and Rowlingson Beehive kindly donated by GardenSite Both are bins suited for use in a modern small garden. The Lacewing easy load composter is slated bin has an easy access as all the front slats can be removed.

 The beehive bin makes an attractive feature in a smaller garden  and is easy to fill with a hinged lid and a prop to keep it open when material is being added. Harvesting is by means of a hatch at the base of the bin.

 The material added to the bins on this occasion, as well as including the soil on the roots the  mentioned above, consisted of a mixture of annual and perennial spring growing weeds as the mix in the reception bin made it impractical to separate them. While the official advice is not to add any roots from perennial plants many allotment gardeners just put everything in the bins  usually with out significant problems. Any  perennial weeds that  survive the composting can be removed at the end of the process. Progress will be monitored in future blogs. More information on the site and training available  can be found at and