The Compost Guy behind Hot Composting Week

The kids in the Johannes household have a ripping time on Saturday mornings – that’s when they join their dad tearing up cardboard for the family’s compost bins.

Their dad Adam Johannes is best known to his customers and Instagram followers as Compost Guy.

Adam had long been a keen gardener and composter when he realised a few years ago that he could help other people by offering advice to newbies starting out on their own composting journey, as well as selling products that he believed in, including the Green Johanna.  People message him with their questions and he aims to respond to 99 per cent of queries on the same day.

Adam – a regular Compost Guy

He finds that most people who contact him have already convinced themselves to start composting but just need a bit of advice.

‘They argue themselves into it, they know they want to send less to landfill, be more sustainable, and get compost,’ he says. ‘If someone is not completely sold on it, I normally list out the practical benefits, then the issues with not doing it!’

In a bid to spread the word, he decided to start an annual Hot Composting Week – the first one begins on Monday (September 18 – 24). He got the idea because he realised there were other weeks dedicated to general composting, but nothing focused on hot composting ‘- and that is the best way!’

He uses hot composters himself – a Green Johanna and Hotbin – and has also used Aerobin, wormeries and Bokashi bins in the past.

 ‘I thought it would be good to highlight the benefits to more people. Everyone is surprised when I tell them how hot it gets! The aim of the week is to show people that hot composting is a good investment for them, and the planet.’

 Concern for the environment

Compost Guy started life in the winter of 2019, a few months before the pandemic hit. Adam found that customers were initially motivated by concern for the environment; then when garden waste collections stopped during lockdown, there was an additional reason for people to get into composting – to get rid of the garden waste they were stuck with.

He stresses that his small team are not scientists or professional gardeners, just enthusiasts who believe in the value of what they’re doing and know there are people out there who would benefit too. Composting started as a natural extension to gardening for Adam but quickly became a hobby. As an allotmenteer he originally wanted to find out how to enrich his soil for best results.

‘Composting is a great hobby for anyone,’ he says. ‘Sad as it sounds, I love getting out there and aerating my compost. I like the hands-on nature of it. Perhaps I love composting far too much!’

Compost Guy’s enthusiasm seems to give people the confidence to reach out and ask him all sorts of questions.  He loves trying to help and points out that everybody’s compost bin will be different, depending on various factors, such as the bin’s contents, position, local climate etc.

The main questions he gets asked are about how to speed up composting and the differences between the various hot composters.

Carbon content

When he first started on Instagram he only expected a few followers but to his astonishment quickly got far more – to date he has an impressive 6,700.
He sorted out a potential problem for his own in-laws recently when they were just starting out with their Green Johanna. On inspecting their Johanna, Adam saw that food waste had not been mixed with much garden waste and was sitting on a large amount of grass clippings which had matted together. So he set about ripping up cardboard boxes, with his children of course, and added this to the bin along with shredded waste paper. They tore up more carbon-content waste than they needed and put the excess in a handy lidded container to store it for when needed later.

 A video on the website shows Adam enthusiastically aerating the Johanna’s contents to bring back ideal conditions in the bin. He also used a garden fork to aerate deeper in the bin to break up the matted grass and added bark chips, which provide valuable air pockets.

Adam is keen that Compost Guy should be a force for good in the world. A good portion of the profits go to sponsoring three children in poverty and each new customer means trees get planted with Just One Tree – up to July 2023 more than 2,073 trees had been planted.

In addition, Adam is a trustee and contributor to the Veg Box Donation Scheme, a charity which accepts surplus produce from gardeners for the benefit of others, and he also supports Transform Trade.

A few people who will surely never need to consult Compost Guy for advice are the Johannes juniors, who are learning valuable lessons every day – in life as well as composting.  

Digging into myths about gardening

Did you know:

  • Using a petrol-powered lawnmower for 30 minutes produces as much air pollution as a 50-mile car trip?
  • Chemical fertilisers that are washed by rain into water sources suffocate marine life?

These are statistics unearthed by Dr Stuart Farrimond, in his latest book The Science of Gardening: Discover How Your Garden Really Grows.

 Dr Stu is a medical doctor turned science writer whose books explore the science behind everyday life. You may know him as the food scientist on the BBC show Inside the Factory.

His aim with The Science of Gardening was to write a book about the basics from the perspective of an outsider in the gardening world.

He says, ‘For something as beautifully simple as sowing, planting and watering we humans have made gardening terribly complicated.’

With this in mind he strips away the gobbledegook, strange rituals and debunks popular myths.

The sections on sustainable gardening look at the environmental impact of the choices we make in our homes and gardens. For those gardeners who compost already or would like to start, the chapters about composting explain the process in a straightforward, fascinating way.  

To return to the point above about petrol mowers, Dr Stu asks gardeners to consider whether instead of using petrol-powered mowers, leaf blowers or hedge trimmers they could switch to hand tools or electric alternatives.

He points out that:

  •  The use of synthetic fertilisers can pollute waterways, whereas soil that is enriched with mulches of organic matter can supply plants with all the nutrients they need.
  • Chemicals used to control weeds, pests and fungal diseases can have unintended consequences as they are by definition poisonous to life. Less harmful ways to limit damage by pests include using methods such as ‘integrated pest management’. 
  • You can plant and manage your plot in ways that maximise its ability to store and retain carbon dioxide.
  • Covering soil with woodchip, compost, straw or rotted manure (mulches) in late autumn protects it from pummelling winter rainfall (each bullet-like drop travels up to 20mph).
  • Soils that are fed annually with organic matter and where digging is minimised will store more carbon than those that are regularly tilled.

Topics covered also include why gardening brings joy, comparisons of different techniques and how to encourage first shoots.

Dr Stu describes gardening as ‘the perfect antidote to doom-scrolling through today’s news, it reconnects us with the perpetual cycle of life, death and renewal of which we are all a part. In fact I can think of no other pursuit that offers more.’

Here are just a few of his Myths v Science findings:  

Pruning cuts should be made at an angle

 Flat cuts heal faster; angled cuts leave a larger wound and do not prevent rot by stopping water pooling on the stem.

A layer of crocks or stones at the bottom of containers improves drainage

 The popular advice to prevent fungal root rot in plants in water-logged soil is to place pieces of broken pots (termed ‘crocks) or gravel into the pot before topping up with potting compost.

However, plants in pots with crocks fare no better than those without. The small pores between soil particles hold onto water like a sponge, so that it does not easily flow into the much larger spaces between crocks or gravel. Instead water clings to the lowest layer of soil, where it can accumulate and cause drainage problems. The best advice to avoid water logging is to use good quality potting mix, a pot with drainage holes and to not overwater.

Talking to plants benefits their growth

Science shows that plants feel the air vibrations that cause sound and grow faster when placed in front of speakers playing a continuous tone or music. This is possibly because they have evolved to sense the wind and contact from animals and insects, and this stimulation is a natural part of their development. It seems unlikely that occasional words would boost growth, although it has never been conclusively proved one way or the other. Human breath also contains high levels of carbon dioxide, which plants use to make food via photosynthesis but whether this fleeting increase affects growth is unknown.

The staff here at Great Green Systems have found this book a great read and source of reference. It would make a perfect present for any gardener, whether newbie or old hand, especially when the gift-hunting season which shall remain nameless comes around in a few months’ time.  

Taking compost from the Green Johanna


At Great Green Systems we’re always keen to share our and our customers’ experiences of composting with the Green Johanna. This weekend we opened up a Green Johanna that we have been trialling with great results.

This Green Johanna was used from mid-September 2022 to mid-February 2023 with the insulating jacket permanently installed.
100% of the cooked and uncooked food waste from this household was recycled in the Johanna. There were between 2 and 4 people in the household during this time, with up to four more visiting through the Christmas and New Year period. The amount of waste diverted to the residual (grey/black) wheeled bin fell to less than 50% of the bin capacity (ie less than 120 litres) per fortnight compared to previous usage. Over the Christmas period, when bin collections were suspended for a week, the residual bin comfortably coped with three weeks’ worth of general waste.
The fermented contents of several 14-litre Bokashi bins that were accepted from relatives who don’t have their own compost bin were also decanted into the Green Johanna.
The food waste was liberally mixed with carbon-based materials, mainly autumn leaves and wood chips, and treated once per month with Bokashi bran to accelerate the composting process.
Using this method, we consistently achieved compost temperatures of 30-60 degrees Celsius even through the coldest winter temperatures. All the food waste generated from the household was comfortably accommodated by the composting system.

Saving the top section to go back into the compost bin

Compost can be accessed by unscrewing the hatches at the bottom or, since the Green Johanna is a modular unit made up of circular rings, the upper sections can be removed leaving an impressive tower of compost. As you can see from the photos, we chose the second route as we wanted to take a lot of compost out at once.
We removed the top sections of compost that are currently decomposing (taking care not to squash any worms) and placed these on an old wipe-clean tablecloth kept for this purpose until we were ready to put them back in the bin to continue the breakdown process.
More than half of the composter contents were removed for soil replenishment and other garden uses, with the remainder being returned to the Johanna for further composting.

Topping up planters with compost

To purchase a Green Johanna Complete Bundle, including Insulating Jacket, click here:
Green Johanna Complete Bundle – Great Green Systems
To upgrade your existing Green Johanna with an Insulating Jacket or Complete Accessory Set, click here:
Green Johanna Insulating Jacket – Great Green Systems
Green Johanna Accessory SetGreen Johanna Accessory Set – Great Green Systems
To combine your Green Johanna with indoor Bokashi Bins, click here: Bokashi Bin By Maze – Great Green Systems
To improve and accelerate your Green Johanna composting with Bokashi Bran, click here: Bokashi Bran 1kg – Great Green Systems

Compost – let’s all spread the love

As unashamed compost-heads feeling the love for the earth this Valentine’s Day, we thought we’d fill a space on the Great Green Systems office wall with this DIY picture.   

And perhaps we should compose (decompose?) a little ode to compost while we’re at it:

 Compost, how do I love thee?

Let me count the ways…

(with apologies to Elizabeth Barrett Browning)

Perhaps it would be better in prose.

Why we love compost

Let’s just start by saying that you don’t need to be a gardener to compost. That is a wrong-headed assumption some people make and if that’s you, we hope we’ll manage to change your mind.

Many of our customers know nothing about composting at the outset but they start because they want to take control of their own food and garden waste. 

Composting used to be thought of as a side-line to gardening, but now more and more people are taking it up because they want to live a more sustainable life and do something to fight the climate crisis.

Compost is an ally in combatting the climate crisis because it boosts soil quality as well as helping soil to pull carbon out of the atmosphere and sink it back into the ground. The more carbon that is taken from the atmosphere, the better chance we have of reducing the rate of global warming. Along with oceans and forests, soil is an important carbon storage medium.

An American study showed that spreading half an inch of compost over half of California’s grasslands could remove carbon from the air at such a significant rate that it would balance the greenhouse gas emissions for the entire state of California for a year.

The International Compost Alliance, formed in 2021 to raise awareness about the benefits of composting, says: ‘Compost is a win-win solution to climate change – not only does recycling organic wastes reduce emissions, compost also brings many benefits when used on soils too.’

Compost boosts soil quality by:

  • holding on to important nutrients
  • improving plant productivity and quality
  • protecting plants from pests and diseases
  • preventing erosion
  • improving drainage
  • absorbing water, slowly releasing it to grass and plants so they need watering less frequently.

As compost breaks down, it delivers important nutrients into the soil. Compost contains the three primary nutrients that plants need: nitrogen, phosphorous, and potassium. As well as feeding the plants that grow in this soil, compost also increases the number and variety of beneficial bacteria and fungi in the soil, which helps plants to grow.

The quality of produce grown in soil treated with compost tends to be higher. International studies have shown:

  • In India – quinoa plants in soil mixed with compost showed a significant increase in ability to take nutrients from the soil.
  • In China – wheat fields treated with compost had significantly increased yields versus a control field of uncomposted soil.
  • In Italy – compost increased lettuce and kohlrabi growth by 24% and 32% respectively.

Studies on compost’s water-retaining abilities have shown that for every 1% of organic matter content, soil can hold 16,500 gallons of plant-available water per acre of soil down to one foot deep.

Compost also helps water to get to plant roots more effectively by:

  • reducing crust forming on soil, so water can get into the soil more easily.
  • helping to disperse water laterally from where it hits the ground, which means it will evaporate less quickly.

What a waste

Once you start composting you begin to realise the amount of food that is wasted and its cost. This awareness tends to help households to reduce food waste in general.

Food and garden waste account for more than 30% of the contents of a typical domestic wheeled bin, which is crazy when you think that this waste could be turned into free soil nutrition that can replace or reduce costly chemical fertilisers.

Around 50 per cent of local authorities in England have yet to begin separate food waste collection schemes, so there are still mountains of food waste being sent to landfill or incineration for the foreseeable future.

Engaging in the composting process also introduces children to environmental science. This is a topic that can grow in complexity as a child grows and is able to understand more about what is involved.

According to the charity Garden Organic, the health of the earth’s soils is fundamental to life as we know it, yet half the planet’s topsoil has been lost in the last 150 years.

Save our soil

There are around 15 million gardens in the UK – that’s millions of people with access to a patch of the planet. The charity urges people to take simple steps to redress soil degradation in their own gardens by regularly topping up beds with compost and ensuring soils are not left bare.

Bare soil is vulnerable to erosion, weeds and carbon loss. So even if you don’t need compost for the sake of plants, covering bare soil is still beneficial for the environment.

You can also spread compost thinly across a lawn or grassed area, where worms will pull it down into the soil and it will boost soil quality and by extension the grass.

Or give it away – to allotments, community gardens, school gardening clubs, voluntary groups. It will always be gratefully received.

Compost – spread the love.

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