When is my compost ready to use?

This was a question that two new owners of a Green Johanna were asking themselves in their first year of composting. 

Adam and Hayley decided to try composting with a Johanna last year following a few failed attempts with other composters.

They’re both vegans and wanted to produce their own compost to use for growing their own veg, as well as recycling their food and garden waste sustainably.   

  The standard test for when compost is ready for use is that it is dark brown in colour, crumbly in texture and has a pleasant, earthy smell like damp woodland. If you’ve been hot composting, the mature compost will no longer be generating heat. The original materials should not be recognisable. There may be a few items that have not fully broken down, such as sticks, bits of tea bags, corncobs, eggshells, fruit stones, compostable bags – these can be picked out and added back into the next batch of composting material.

 If there are other recognisable waste items and an unpleasant smell, the compost is not ready and should be left to continue breaking down.

Master composter Rod Weston, in his book A Gardener’s Guide to Composting Techniques, suggests a test to check if compost is ready if you are wanting to add it to soil immediately (immature compost added to soil can cause a temporary reduction in the availability of nitrogen and oxygen and create root-inhibiting organic acids).

The test involves putting a handful of compost in a plastic bag and sealing it for three days at room temperature. If when opened the contents have a pleasant earthy smell, composting is complete.

 Rod suggests that during the growing season immature compost is best used as surface mulch. If mostly composted it will finish breaking down in the soil. In autumn and winter it can be dug into garden beds. Some people prefer to leave their compost breaking down over winter to have it ready for the start of a new growing season. 

Horticulturalist and author Charles Dowding encourages a relaxed approach to the final product. In his No-Dig Children’s Gardening Book (also a good read for adults) he says that mature compost can be anything from ‘slightly lumpy and fibrous to quite fine and soft’. It all depends on the materials that went into making it and they will all decompose at different rates.

‘It doesn’t need to look perfect – woody bits in your compost make great food for fungi.’

He cautions against sieving compost as it can damage microbes.

What’s the difference between compost and humus?

The term compost describes materials that are still breaking down whereas humus is what’s left when breakdown is no longer taking place and the usable chemicals in the organic matter have been extracted by the micro-organisms.

It takes years for compost to decompose into a humus state. Even mature compost isn’t really ‘finished’ since bugs and fungi still have material to work on. Some gardeners have a bank of composters and leave the final one to break down completely into humus.  

A bumper crop

Adam and Hayley decided to leave their compost for about a year so they could use it in a compost mix for growing potatoes.

With first-time use of a Green Johanna, it can take 6-8 months for compost to be ready for use. After that, depending on conditions, it’s usually 4-6 months. With regular cold composting it’s usually between 6 months to 2 years.

Great compost accelerator

The couple also used a bokashi bin alongside their Johanna.  The pre-compost that a bokashi bin produces makes an excellent compost accelerator, raising temperature and speeding up decomposition. Fermented bokashi mixture is usually quite wet so needs to be balanced with plenty of carbon-rich materials. The bokashi mixture will then break down in the composter. 

 ‘Bokashi has become a really useful part of our composting process,’ said Adam. ‘We put all our food waste straight into the bin and give it a few sprays of Bokashi spray, then once it’s full and has been left to ferment we transfer it to the Johanna.’

It usually takes them around one to two weeks to fill the Bokashi bin with their kitchen waste, which is usually vegetable scraps along with some beans. They then use their smaller kitchen caddy to take food waste to the Johanna while the Bokashi bin is ‘doing its thing’.

Food waste provides the compost mix with nitrogen-rich content, which must be balanced with shredded carbon-rich materials (dead leaves, twigs, branches, wood chips, paper waste) and regularly aerated to get oxygen into the pile.

The verdict on the Johanna:

With previous composting attempts, the couple had experienced slow breakdown of waste materials with hardly any compost produced.  

 ‘The Johanna is much better built and works faster at breaking down all the waste,’ said Adam.

The couple feel their efforts with the Johanna and Bokashi have paid off – not only are they recycling all their food and garden waste nature’s way, but they also get to make their own delicious home-grown spuds. What’s not to like? 

Which composter is best for me?

An image of a green johanna

If you’re new to composting it can be difficult to know which bin (or system, if you like to think in systems rather than bins) is best for your home and lifestyle. Our handy guide can help.

Food waste composter/digester

The Green Johanna Hot Composter and Green Cone Food Waste Digester are both designed to accept foods that regular garden composters don’t, such as cooked food, meat, fish and dairy, so all your food waste can go in together. Compare them to see which one best suits your needs.

Green Johanna Hot Composter

  • Produces compost.
  • Also accepts garden waste.
  • Added waste should be a balance of nitrogen-rich content, commonly called Greens, (food waste/fresh grass cuttings/fresh green leaves) and carbon-rich content, commonly called Browns (chopped branches and twigs/wood chips/dead leaves/shredded paper and cardboard).
  • Comes with aerator stick provided to aerate the contents regularly.
  •  Ideally placed on soil or grass
  • One Johanna accepts the average food waste of a household of five and the garden waste from an average-sized garden.
  • With hot composting techniques, higher temperatures are reached than with regular composting.

Green Cone Food Waste Digester

  • Must be dug into a hole in free-draining soil (not clay or chalk).
  • Accepts all food waste, even bones.
  • Doesn’t accept garden waste or paper waste.
  • Doesn’t produce compost – instead it produces nutritious water which drains from its underground basket and feeds surrounding soil.
  • No turning or stirring required.
  • Uses solar energy so requires a sunny spot.
  • Comes with kitchen caddy provided.

Compost Tumbler (by Maze) 180 litre/245 litre

  • Takes kitchen waste and garden waste. Accepts cooked waste if chopped up into small pieces and mixed in well with other waste.
  • Cylindrical rotation design makes turning compost easy. Instead of manually stirring you turn the ratchet handle. The geared ratchet automatically locks rotation in any position.
  • Two compartments mean non-stop composting – when the first compartment is full you start on the second.
  • Can be hardstanding.
  • A cart is available so that finished compost can be removed and wheeled where you want it in the garden.

Traditional Garden Compost Bins

  • Usually used for cold composting at low temperatures.
  • Only take raw fruit and veg scraps, garden waste and paper/cardboard.
  • Require a 50/50 mix of nitrogen-rich Greens and carbon-rich Browns.
  • Available in plastic or wood. Plastic bins tend to be more robust but wood may be preferred for a natural look. 

Lack of space?

Worm farms

Worm farms, also called wormeries, are ideal for small-scale composting and for introducing children to the fascinating world of worms, which is an education in itself.

  • Require a sheltered spot.
  • Worms will digest many kinds of foods cut up into small pieces and other kitchen waste such as shredded paper, egg cartons, scrunched up newspaper.
  • A little management is needed to maintain the ideal environment for your worms, so be sure to read the instruction booklet.
  • Produce excellent worm-made compost – vermicompost – for your garden.
  • Learning fascinating facts about these tiny eco-heroes is sure to turn children into composters of the future.

Bokashi Bins

14 litre Maze Bokashi Bin
  • Kitchen food waste bins that can sit on a worktop or under a sink and accept all chopped-up food waste.
  • Food waste is fermented, resulting in a pre-compost mixture which can be added to a compost bin or wormery, buried in soil in the garden or in large planters in order to break down into compost.
  • Requires the addition of friendly bacteria in a bran or spray to accelerate fermentation.
  • When full of food waste, the container is left sealed for two to three weeks for fermentation to take place anaerobically (without air).
  • Nutritious liquid is drained from a tap at the bottom of the bin and can be used diluted as plant fertiliser or concentrated as organic drain cleaner.
  • Bokashi comes from the Japanese term for ‘fermented organic matter’.

Choosing a compost bin – by the experts

This advice – taken from a webinar by master composters from Garden Organic – provides extra help.

Wooden bins – a sustainable material – cheaper – allows the pile to breathe – looks natural and attractive in the garden – don’t add meat, fish, dairy or cooked food due to lower temperatures – a few bins can be placed together, with one or two left to mature while one keeps working.  

Blackwall compost converter – the most common bin – affordable – long-lasting – made from recycled plastic – useful for getting compost out (the bin can be lifted up and removed like a jelly mould) – a base plate is available but an added deterrent to rodents can also be achieved by digging the composter slightly into the ground and putting a  wire mesh under the base – channels of air can be created by plunging a broom handle into the contents.

Green Johanna – reaches higher temperatures – as an enclosed unit it offers greater rodent protection – the twistable top controls ventilation – the solid perforated base means liquid can drain out and micro-organisms can enter – if adding meat, add small amounts, mixed with lots of greens and browns – aerate the top layer every time you add materials – for speedier composting an insulating jacket is available. An alternative way of taking compost out, rather than accessing through the hatches, is to loosen the screws and lift off one or two sections.  Composting slows down in winter but the Johanna continues well and does better than other composters.

HOTBIN – versatile, takes all food waste and also perennial weeds – produces compost quickly – useful in school gardens – contains air channels – needs woodchips as a bulking agent – has a hard surface to discourage rats nesting underneath – requires more attention – more expensive but versatile.  

Wormery – small and self-contained – ideal for small amounts of waste – year-round composting – can be indoors – worms eat the bacteria on the organic matter – no spicy foods or citrus, only small amounts of meat – food scraps are placed on the top section, casts fall to the bottom. Use the worm-made compost on pot plants or round trees and shrubs. NOTE: If the liquid that is produced smells bad it has gone anaerobic and should be flushed away.

Also:

  • Wormery compost is a great improver to shop-bought compost; you can buy the cheapest of composts but turn it into black gold with the addition of your vermicompost.
  • Sheds are not a good place to house a wormery due to temperature fluctuations – a garage or indoors is better.
  • If you need your worms to move out of way as you harvest casts, add melon or banana – worms love these and will obligingly wriggle over to them.  
  • Don’t forget that with a wormery you are responsible for living creatures.

Bokashi bin – ferments waste instead of composting so the contents need to be transferred to a composter after a couple of weeks – this pre-compost  acts as an activator in your compost bin – Bokashi bran is needed – fermented contents of the bin will still be recognisable (some people expect compost) – produces liquid which can be used as a drain cleaner or diluted as fertiliser – good to use two bins to keep the process going – ongoing bran purchase required.

Tumblers – compost is kept off the ground so rodents are deterred.   

Electric kitchen composters – these grind waste as opposed to composting it.

Ridan – giant tumblers with a cog and gear system that makes the handle easier to turn – popular in schools and businesses.

Johannas give hope to South African townships

There can’t be anywhere on earth putting Green Johannas to better use than the townships of South Africa.

The food waste composters are a vital tool there in the work done by local women to sustain their families, communities and the environment.

The women, known locally as Kamammas (‘mothers who carry their child and community’), use the Johannas to recycle food waste into compost to grow their own food.  They then use this produce to cook traditional homemade cuisine for tourists who stay in their guest houses, providing a true taste of the real South Africa.

A Kamamma and Johanna

These ‘Homestay’ experiences are organised through the Dreamcatcher South Africa Foundation, a non-profit social enterprise which gives communities, especially women and youth, the opportunity to raise themselves out of poverty through training and employment.

Township residents are trained as hosts, guides and small business owners, enabling them to introduce tourists to the culture of their country.

Dreamcatcher’s founder Anthea Rossouw remembers the Kamammas’ reactions when she first showed them how they could learn to compost using a Green Johanna (shown in the video below).

‘Their reaction was amazing. Such joy, because they could see what this meant for them – to be able to grow their own food.  They started singing – ‘Give Me Hope Jo’Anna’ and dancing round the compost bin!’

Dreamcatcher’s recycling work is now even more important since the South African government has committed to halving food loss and food waste by 2030.  In recent months Anthea and her team have been running workshops to get more people recycling their food waste with Green Johannas.

A lorry load of Green Johannas destined for South Africa

The idea for Dreamcatcher came to Anthea more than 30 years ago during the apartheid era when she knew she had to do something about the suffering she saw around her.

‘There was so much injustice, inequality and insanity on a human level and an environmental level,’ she says. ‘It was obvious it couldn’t continue.’

Raised in South Africa by parents who championed diversity in defiance of the apartheid system, Anthea believes in turning challenges into opportunities.

Her father, a master builder of English descent, used to tell her, ‘Forget the pie in the sky and get down to earth.’ He could never have imagined how literally his daughter would take that advice, as getting people composting is one of the many strands of her vision for a better world.    

Over the years she has run many composting workshops, both in South Africa and the South of England where she divides her time.  She reckons that 99 per cent of the people she talks to have never composted before, but before long they are as evangelical about it as she is.

‘Composting is all upsides – you’re taking food waste out of landfill, where it’s an environmental disaster, and out of homes, with all the health and hygiene issues that involves. And it creates free, organic compost for people to grow their own food and flowers.’

When starting Dreamcatcher, she felt that an answer to many of the problems faced by townships could be found in a new kind of tourism. The tourism industry at the time was booming but completely bypassed the townships, with tourists being driven straight past the communities as though they didn’t exist. She saw a way for the inhabitants to share a piece of the tourism pie by offering visitors the chance to ‘life-see’ as well as sight-see.

A Kamamma gives tourists an authentic taste of South Africa

Anthea’s first proposals centred on the community of Melkhoutfontein, Western Cape, which at the time was one of the most destitute areas in the country, situated between two rubbish dumps and surrounded by waste.

The response from the authorities was ridicule. ‘The attitude was, “But no one will want to go there, no one will want to eat there!” ‘

 But Anthea connected with the international marketplace, convinced that tourists would relish the chance to meet the people (as well as the elephants!) of South Africa, thereby getting to know the soul of the country, not just its beauty spots. And she was proved right. Since its inception, Dreamcatcher has facilitated trips to South Africa for hundreds of tourists from over 30 countries.

Dreamcatcher developed authentic tourism experiences led by local people. It is based in the region that boasts the earliest known examples of human artistic activity, in the 73,000-year-old drawings discovered in the 1990s at Blombos Cave.

 Homestay with Kamamma

Focusing on struggling areas situated within established tourist routes, Dreamcatcher gives people the skills and knowledge they need to support themselves. Then, armed with these new skills, they develop enterprises such as ‘Homestay With Kamamma’ and ‘Cook-up With Kamamma’ and they go on to mentor others in the community

Educational programmes help to transform children’s lives, breaking the cycle of poverty. A good example of this transformation is one Kamamma who has three children – one is now a trained chef, one is training to become a teacher, the other to become a doctor.

Anthea knew that tackling waste was essential to Dreamcatcher’s tourism aspirations. So she set up a waste education scheme called ‘Waste – it’s Mine, it’s Yours’ in collaboration with the University of Brighton. She describes the waste problem in South Africa as a legacy of apartheid, when the dumping of waste was a way of expressing opposition to the system, as well as a protest against the lack of infrastructure caused by the forced removal of citizens. Moreover, in many communities the inadequate infrastructure led to waste being openly burned in the community or at dumpsites. Over time, waste and litter became a way of life, so training was invaluable in introducing the best ways to manage waste. An environmental ethos soon followed with local people taking pride in their role as custodians of their environment. And what a stunning environment it is!

Rubbish as a resource

Waste is no longer seen as rubbish but a resource. Dreamcatcher has created a thriving crafting industry, with tuition provided by visiting artists, so that young people can intercept waste that might end up on the beautiful beaches and in the ocean and turn it into craft products to sell to visitors. Plastic films are turned into bowls depicting the rich cultural heritage of the area, porcelain pieces incorporated into tiles to embed in walls and old jeans and waste textiles are transformed into bags and backpacks.  

Anthea is understandably proud when describing how mass-produced items that are deemed worthless can be given value thanks to the skill of a local craftsperson.  

The University of Brighton partners with the Dreamcatcher community. With the help of visiting volunteers and artists, local people have transformed the sides of buildings with brightly coloured paintings that tell the stories of their ancestors – bushmen and women with a rich history and many diverse cultures.

A volunteer takes compost from a Johanna

So how did Green Johannas come to play a part in this story?

Anthea first worked with Green Johannas through a community composting project she started when she was living in West Sussex in England in 2008. She took the same method of training back to South Africa, where she knew it would be transformative.

She believes the fact that the Kamammas were already producing their own food meant they were protected from some of the hardship caused by the Covid pandemic.

Inspired by a Nelson Mandela quote – ‘Something is only impossible until it’s done’ – Anthea says she is excited to see what can be achieved over the next few years.

A daily source of inspiration are the Kamammas themselves.

‘When I first met them I was overwhelmed by their warmth and generosity,’ says Anthea. ‘Each woman brought something from the little she had to make me welcome.

‘These are women who were rejected by their own culture, who had to struggle to raise their children but succeeded in sending them to university. They are survivors every day of their lives. They’ve gone from being servants to service providers.’

Great Green Systems couldn’t be prouder to be part of the Kamammas’ inspiring journey.

Locals learn how to use the Johanna with Anthea, right.

Tips to deal with fruit fly nuisance

One summer several years ago our house was besieged by an infestation of fruit flies, the source of which was eventually tracked down to a rotting, black banana under my teenage son’s bed.  It is known in the family as Bananagate and is still referred to even though the son in question is now nearly 30.

If fruit flies happen to you once, you will make sure they never happen again. They are a common nuisance in the UK, affecting more than 60% of households.  Each female may lay as many as 500 eggs and they proliferate quickly.  

They’re most common in summer and autumn because they’re attracted to ripe and rotting food, especially bananas, melon, tomatoes, squash and apples. The smell attracts adult flies, which lay their microscopic eggs in the fruit skins. The eggs might already be present in fruit that you buy or get from the garden. If you then put the rotting fruit or peel into your food waste caddy and then into your garden composter you might be unwittingly transferring fruit fly eggs to the compost to hatch out later when the temperature is right.  

Good composting management usually keeps flies away.   

A few flies can be beneficial since in the compost food web they are considered physical decomposers, helping to break down compost material. Their eggs are also a source of food for other compost creatures. But flies breed fast and if there are a lot of them it’s both a nuisance and a sign that something has gone wrong. 

Their presence is likely due to the following issues in the bin:

  • Lack of oxygen – when there is not enough air, composting is slow and the temperature drops – conditions which attract flies. So add oxygen by aerating with an aerator stick. You can also poke holes in the compost with an iron bar. Deep aeration also disturbs the fly reproductive cycle; some types breed every five days. 
  • Too much moisture – the water content should be about 50 per cent. If there is more water than this, it can force air out, which leads to anaerobic conditions (without air) causing slow decomposition and bad smells, which attract flies. You can monitor compost moisture levels by testing with a moisture meter or by squeezing it in your hands. If it feels like a wrung-out sponge, it has the right consistency. There should only be one or two drops of liquid visible. If it’s wetter than this, add some absorbent material such as shredded paper or sawdust and aerate.
  • Imbalance of materials – a mixture of materials high in carbon (Browns) and nitrogen (Greens) is recommended for active composting. Aim for roughly half and half of both.  
  • Poorly-covered nitrogen-rich materials (Greens) – bury smelly foods in the compost, wrapped in newspaper if possible. Create a covering layer over the top to capture smells. This can include straw, sawdust, wood chips, soil or mature compost.  A fly-proof mesh over the top of the contents will keep flies out while allowing air in.  

As the compost becomes active, with raised temperature and faster decomposition, the fly infestation should end.

A word about fruit waste

If you add large amounts of fruit waste to your composter be aware that this will be high in water content. To avoid making the compost too wet (which attracts flies) it should be well mixed with equal amounts of dry carbon-rich content, such as woody garden waste, dead leaves, shredded paper/cardboard, wood chips, sawdust. An equal addition of sawdust, for instance, would be an effective way to absorb some of the moisture in fruit waste.

To avoid attracting flies, reduce the smell of fruit by wrapping it in newspaper and burying it in the existing compost, then cover with carbon-rich content and add mature compost or soil over the top. 

 Take these steps to reduce the chance of attracting flies.

In the home

  • Because fruit flies lay eggs on exposed food, take care to keep food stored in a fridge or lidded containers, not out in the open in fruit bowls.
  • Use up ripe fruit and vegetables as soon as possible.
  • Compost organic matter quickly as flies are attracted by the smell of decomposing food.
  • Keep stored waste in a lidded kitchen caddy. Always keep the lid on your caddy, even between new additions of waste as you are preparing food.

In the compost bin

Follow the steps mentioned above regarding composting management and also:

  • Add more carbon-rich materials (woody garden waste/shredded paper/cardboard/wood chips), and mix in well so that any food waste is covered.
  • Top the contents with a layer of fresh soil.
  • Try putting the composter in sunlight – flies like a warm but not hot environment.
  • Make sure that you always lock the lid securely.
  • Take care not to spill any food around the composter.
  • Monitor acidity – if you have added a lot of fermented content from a bokashi bin to your composter, add a handful of crushed baked eggshells to neutralise excessive acidic conditions as flies prefer a low (acidic) pH.
  • Flies don’t like the smell of certain plants – peppermint in particular – so you could add sprigs of peppermint to your waste and wipe round the compost bin with lavender, lemongrass, eucalyptus and peppermint essential oils.
  • Leave the lid off the bin for a while to allow predators such as ground beetles, rove beetles and earwigs easy access to the flies.
  • Use nematodes – microscopic worms that feed on fly larvae in soil.  

In the Green Cone

 In the case of the Green Cone Food Waste Digester, no garden waste can be added as the Cone only accepts food waste, so covering with garden and paper waste is not an option.

Because the Cone’s basket is underground, smells are filtered out by the surrounding soil, meaning there is no obvious attraction for ordinary flies. But if fruit fly eggs are already in fruit skins when added to the Cone, they might hatch inside it. Avoid this by following the advice above on preventing infestations in the home.

Also:

  •  Freeze your fruit and veg scraps in a plastic bag or container overnight to kill any eggs or larvae before adding them to the Cone.
  • Flies don’t like the smell of certain plants – peppermint in particular – so you could add sprigs of peppermint to your waste and wipe round the Cone with lavender, lemongrass, eucalyptus and peppermint essential oils.
  • Add accelerator powder to add more beneficial bacteria to speed up decomposition.
  • Remember food waste should never come higher than the top of the Cone’s underground basket; waste should always be below ground level.

 Get trap happy

You could also try a home-made trap that will act as a magnet.

Add an inch of apple cider vinegar to a glass jar with two drops of washing up liquid. Put a plastic wrap cover over the top of the jar and poke small holes through with a toothpick. Flies are attracted by the smell and can get in but can’t get out. Remember to change the liquid regularly to keep the fly trap working.

If all else fails, consider disposable fly traps which come pre-filled with bait or attractant and can be placed in the bin. Be aware that these may also kill other beneficial decomposers in the compost.                                                            

Keep food covered to discourage fruit flies.

The book that will keep you composting

You might expect anything written about composting to be down to earth (pun intended) but if you read a lot on the subject, as we do, you’ll know that’s not always the case.

Sometimes you come away from an article thinking you must need a PhD to compost. You wonder how Mother Nature manages without the aid of a spreadsheet and calculator for tracking temperatures and working out ratios. If spreadsheets and calculators are your thing, don’t let us stop you (some of the GGS team are guilty as charged).

But most of us just want simple advice we can follow. That’s why at Great Green Systems we often point customers towards Master Composter Rod Weston’s website (carryoncomposting.com) because it offers straight-forward, practical guidance. So we were delighted to learn that Rod has turned his knowledge into a book.

The Great Green team love this book and anyone who is into composting, or could be with a little encouragement, will love it too. It gives the lowdown on just about every compost bin going so it helps you to understand your own bin better or to choose one that will work best for you.

Rod hopes the book will encourage householders to compost their organic waste ‘and most importantly, to continue composting.’ He acknowledges that people new to composting may encounter various problems while trying to master the craft, but by showing different techniques to deal with issues he hopes to help new recruits to persevere.

‘The key message is to keep composting, whatever style you adopt,’ he says. ‘All techniques can be modified to suit your own particular circumstances.’

He also hopes to encourage groups to set up small-scale community composting on allotments, at schools, and on community gardens. He points out that if garden and catering waste can be dealt with on site, the environmental costs of transporting it to a central location for processing can be avoided.

We recently paid Rod a visit at the Stokes Wood Allotment site in Leicester, which includes a demonstration site that is home to every composter you can think of. Rod demonstrates different bins and techniques to the public.  

The site provides a community composting service for allotment plot holders and also takes food waste from the café on site. Plot holders leave their waste for composting in designated spots and can take compost (and liquid feed) for their own use when it’s ready.

Working bays and bins at Stokes Wood Allotments composting demonstration site

Rod’s book also explains the idea behind the Master Composters scheme. In 2004 around 40 per cent of householders who had started home composting gave up because of a lack of knowledge. Almost two decades later, councils and others now produce information and train Master Composters to provide support. This has resulted in a reduction in the dropout rate to between 8 and 14 per cent. In more recent years this has reduced again to 3.9 per cent. Obviously the scheme has been a great success.

Like many of his generation, as a child Rod helped his father on his allotment ‘in the days when allotments were an important piece of ground that played a major role in providing fruit and vegetables for the family’.  

Before becoming interested in the environmental aspects of composting, Rod initially composted on his own allotment in order to dispose of garden waste and to use the compost produced as a soil improver. He says it was his wife who first became interested in becoming a Master Composter ‘but then suggested it to me because she thought it would keep me off the streets!’

On our visit we loved talking to Rod about all aspects of composting. It’s so refreshing in this world of uncompromising opinions to hear his relaxed straight-forward views. Like us he’s pleasantly obsessed but not a purist. Rod’s attitude is that we can all compost – you just have to find a system and bin that works for you.  The more people who compost the better it is for all of us and for the planet.

Anyone living in or around Leicester is lucky to have easy access to his talks and demonstrations.

‘If you are interested and want to get involved with your bin, go for hot composting. If you’re lazy or too busy, just go for a cold system,’ he says.

He goes about the business of promoting composting in a practical, fun way, giving talks to garden clubs, allotment societies and schools.  For school visits, when talking about wormeries he takes along some slugs and snails as well as worms, knowing his audience will approve.

Other props are a soft toy rat and dog poo (spoiler alert – it’s fake) which is used to explain the workings of a wormery used for dog poo.

Sitting pretty – on the dog poo wormery

He thinks composting will become more popular as more local authority food waste collections come into operation, since a lot of people could prefer to compost their food waste in their gardens rather than having it waiting for collection by the council.

Rod is a fan of the Green Johanna and has a couple at home as well as one on the site.

‘It just sits there quietly and gets on with its job, breaking stuff down, with no trouble,’  he says approvingly.

Rod told us that badgers from a nearby wood had recently made a nocturnal visit and tried to get into the site’s Green Johanna, but failed.

We inspected the teeth marks on the Johanna’s lid and Insulating Jacket, proud that the Johanna had stood firm. And this Johanna is 13 years old.

Rod shows Mark evidence of the failed badger attack

The site also demonstrates an old Green Cone, which Rod says has never needed emptying or cleaning.

Apparently the number one problem with Green Cones that people ask him about is caused by the owner not having read the instruction manual properly. The manual states that food waste should never come higher than the top of the Cone’s underground basket, so there should never be food waste inside the Cone itself, which is above ground level.  Rod said he has seen Cones that have been filled right to the top like a composter, which would not be a great problem to have to sort out.

How a Green Cone should work – with food waste only in the underground basket

We appreciated this insight and we intend to make this point much clearer in the next edition of the Green Cone manual so that no one can possibly miss it. Although it’s obviously not much good if people don’t read the manual.

In his book, Rod says: ‘There are almost as many ways of composting as there are composters and, despite what might be read online, there is no single right way of doing anything. If what you are doing works, it must be right for you, although, of course, the method may be open to improvement. The main thing is to enjoy your composting in the knowledge that, while you are improving your soil to produce better crops, you are also, in a small way, helping to save the planet. ‘

Wise words from a Master (Composter).

How Bokashi boosts your hot compost

When it comes to boosting the composting process, we have found a Bokashi bin to be the perfect partner for the Green Johanna.

We recently carried out trials involving additions of fermented food waste from a Maze Bokashi bin to a Green Johanna and found that temperatures in the Johanna rapidly increased as a result.  

For our trials, we re-started a Johanna more or less from scratch, having previously removed large amounts of compost.  Using a permanently installed insulation jacket and large amounts of Bokashi bran and carbon-rich materials, compost temperatures were around 30 degrees Celsius. 

 We added the contents of a Bokashi bin that had been fermenting for 21 days, followed by a full 1kg bag of Bokashi bran.   We then added some mulch and stirred well with a garden fork, before completing the process with a thin layer of mulch. 

 The Johanna was then left for 48 hours.  Temperatures rose to 66 degrees Celsius whilst outdoor temperatures were in the 0-10 degree range.   After 48 hours we re-stirred to spread heat more widely through the Johanna.    Using two Bokashi bins in rotation we repeated this cycle roughly every three weeks and got the same results.

We used the Green Johanna in combination with a regular kitchen caddy (as the Johanna needs regular feeding to maintain the hot composting process), twin-bin Bokashi system, Insulating Jacket, Bokashi Bran as an accelerant and plenty of mulch.

Photos show starting temperature at 30 degrees Celsius/adding fermented waste from a Bokashi bin/ adding Bokashi bran/temperature at 66 degrees Celsius.

The Bokashi process was developed in Japan in the 1980s; the term means ‘fermented organic matter’ in Japanese.  It involves adding all your food waste, cooked and uncooked, to a specially designed airtight Bokashi bin, with the addition of Bokashi in the form of a fermented bran or spray. The food waste is compressed with a compactor to eliminate as much air as possible as this is an anaerobic process.  Once the bin is full, you close the airtight lid and leave for 2-3 weeks.  Many people use two or three bins to keep the process going.

The bacteria (lactobacilli) in the bran or spray will create lactic acid which will effectively pickle the food waste rather than letting it decompose as it would in a regular food waste caddy.  After a week or so, liquid should start to form in the Bokashi bin which should be drained using the tap.   This ‘Bokashi tea’ can be used as a drain cleaner or diluted for use as plant food.

 At the end of the fermentation period the waste food is a pre-compost mixture that can be added to a composter or buried in soil to become a soil enhancer. Its composition is such that virtually all its original nutrients, carbon and energy enter rapidly into the soil.   No greenhouse gases are released to the atmosphere as they are during regular food waste decomposition in landfill.

Bokashi composting has traditionally proven particularly popular in urban environments where traditional garden composting is difficult. 

Mark

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

Tips to send the rat pack packing

Some of our customers claim the Green Johanna is rat-proof as they have never had any problems with these unwelcome visitors.

That is the experience of most people, but since rats have been known to chew through concrete, glass and even some metals nothing can really be called rat-proof.

However, there are steps you can take to deter rodents by making your compost bin and garden so unattractive to them that they will move on to a more accommodating environment.

If there’s a problem with rats locally it’s worth checking whether a neighbour is exacerbating the issue by leaving food out for wildlife. This was the experience of one of our customers, who discovered that his next-door neighbour was getting animal bones from a butcher and leaving them in his garden overnight to feed foxes. The neighbour even thoughtfully left his garden gate open at night to encourage visiting wildlife. But foxes weren’t the only ones coming round for a feast.

 Such issues obviously need to be addressed first. If there is a persistent problem in your neighbourhood consider professional help to sort it out.   

The Johanna has been designed with an integrated base to deter rats. Using the Insulating Jacket also provides another layer of material as well as insulation to help keep temperatures high enough to discourage rats.   

As part of the Green Johanna’s and the Green Cone’s five-year guarantee, Great Green Systems will replace any parts that suffer rodent damage.

Recommended deterrents:

If you can, site your compost bin in an open, uncluttered area as rats hate being exposed. Open space makes them nervous. If you know there is a rodent problem locally, try to avoid siting the bin along fence lines or near log/brick piles and shrubbery or thick vegetation that provide protection for them. Rats have poor eyesight and use fences and walls to run alongside for direction.

  • Protect the composter’s base – place paving slabs or bricks around the base. Placing thorny prunings around the composter will also make access difficult.  
  • Rats hate noise and being disturbed, so bang on the bin with sticks every time you go past so they get the message this is not a peaceful place.
  • One customer recommends creating a stockade fence of bamboo sticks around composters. Push each stick into the ground as closely as possible (easier to do after rain).
  • Keep the bin active. If you’re going away ask someone to keep your composting activity going for you so the bin is not left undisturbed for weeks.  
  • Ensure food waste is well chopped to provide more surface area for microbes and accelerate the breakdown process. Smaller pieces are also easier to stir and mix with garden and paper waste.
  • After adding and aerating fresh contents, finish with a covering layer of shredded paper, cardboard or dead leaves to prevent smells attracting flies or rodents. You can also add mature compost or soil.
  • Aerate composter contents regularly.
  • Keep the mixture moist. Moisture levels should be around 50 per cent. You can use a moisture meter to check or do the ‘squeeze test’ – take a large handful of compost and squeeze. If one or two drops of liquid come out that is likely to be right – the compost should be the consistency of a wrung-out sponge. Add water if needed in summer months, preferably rainwater from a water butt.
  • Place builders’ mesh (available at DIY stores) underneath the composter.  The Johanna already has an integrated base but mesh would provide an added deterrent.
  • Rats hate strong smells so try planting mint round the bin or scatter chopped onion around – refresh the onion every few days.
  • Make a spray using peppermint, eucalyptus or citronella essential oil – use one part essential oil and nine parts water in a spray bottle. Then spray this mixture around the edges of your garden.
  • Also sprinkle chilli powder, cayenne pepper and cinnamon around as well as spreading lavender and bay tree cuttings around the base. The fermented contents of a bokashi bin are said to be a deterrent as rats dislike the sour smell.
  • A niche solution – if you happen to have access to owl feathers then scatter them around your garden.  Rats sense threats easily so feathers from their predators scare them.  
  • An obvious point but sometimes overlooked – be vigilant that you never drop any food waste around a composter, bin or food caddy.

With the Green Johanna:

  •  Keep temperatures in the bin high by fitting the Insulating Jacket when suitable, adding bokashi bran, and keeping the bin filled and aerated. Hot composting generally discourages rodents because of the heat and the fact that food scraps are quickly broken down.
  • When setting up the composter, wait until the composting process is well under way (after four weeks) before adding cooked food scraps.

The composting environment

  • Discourage rats from making a home in your garden or allotment by sealing access under chicken houses, sheds or decking that can provide shelter for them.
  • Keep the area well maintained – check for anywhere that rats could burrow under or through.
  • If you store bird feed or chicken food in the garden, make sure it is in lidded containers and kept off the ground. Sweep up any fallen birdseed as birds are messy feeders. Put paving slabs under a bird feeder so any fallen seed can be easily swept up.
  • Make sure any bins are not overflowing and food caddies are locked tight.
  • Maintain drains – rats can come up through poorly maintained drains.
  • Keep an eye out during bad weather and flooding as rats are likely to be on the move looking for shelter.
  • Rely on rodents’ old enemies – keep a cat or terrier.

With the Green Cone:

  • Ensure that the top of the black basket and the bottom lip of the green outer cone are below ground level, so that any odours are filtered out into the surrounding soil.
  • Never allow food waste to come higher than the top of the underground basket. Food waste should never reach as high as the Cone itself.
  • Press builder’s mesh (available at DIY stores) into the soil of the hole you have dug for the black basket to provide an additional deterrent.
  • Add accelerator powder regularly to boost the breakdown process.
  • Ensure the Cone is in a sunny spot as the digester relies on solar energy to enable efficient digestion.

How to get the most from your Green Johanna

With your Green Johanna assembled, it’s time to choose the ideal location.

Choose a spot that provides a flat surface with free drainage for any liquid produced. Make sure it’s also not too far from the house and easy to get to.

The Johanna has been designed to promote efficient composting. Vents leading in from the base plate allow air to flow upwards into the container. The twistable lid regulates the ventilation system helping you to adjust air circulation and temperature. The container’s round shape ensures there are no cold corners so heat is spread evenly through the compost, and the tapered design means that compost sinks towards the centre of the unit and not to its sides, allowing air to circulate and oxygenate the compost.

If you’re new to composting, a bit of basic knowledge will help you on your way but you will also learn as you go by paying attention to what’s going on in your bin.

Successful composting depends on three essential ingredients: materials, air, moisture.

Composting basics

 MATERIALS – The microbes in your compost bin need a diet that provides a balance between waste materials that are rich in nitrogen and carbon. In composting terms, nitrogen-rich materials are often referred to as Greens and carbon-rich materials as Browns.

Nitrogen-rich materials (Greens) include:

  • Food waste, fresh grass and leaves, plants, flowers, tea leaves, home compostable tea bags, coffee grounds. These items break down quickly and contain moisture so they keep the bin’s contents moist.

Carbon-rich materials (Browns) include:

  • Twigs, branches, dead leaves, paper, cardboard, straw, wood chips, sawdust. These contents are drier and slower to break down.

 A mixture that contains a 50:50 balance of nitrogen (Greens) to carbon (Browns) is a good place to start for composting. You may find that you have a lot more nitrogen-rich inputs (food waste) than carbon so it can be handy to store carbon-rich items such as paper, cardboard and autumn leaves so you have them ready to add with food waste.

 The smaller the waste items are chopped or shredded, the greater the surface area for microbes to work on and the faster the pile will heat up. Items that are added whole, such as apples or carrots etc, will take longer to break down. Egg shells should be crushed or ground. Garden waste should be chopped into pieces no larger than 5cms or shredded.

Getting the nitrogen/carbon ratio right can be a case of trial and error but you will learn quickly through paying attention to conditions in the bin. 

As the micro-organisms break down the waste, they generate heat. As the temperature in the compost fluctuates, the types of micro-organisms present also change.

AIR – The fastest form of composting is done by organisms that need oxygen.  To give microbes air to breathe we need to add air to the mixture by aerating the contents to make sure there’s oxygen throughout the bin.

You can create air pockets by adding the cardboard tubes from toilet or kitchen rolls whole and keeping cardboard egg boxes whole. Waste paper can be added scrunched up so that it provides pockets of air, or shredded. Cardboard should be torn up. Wood chips are useful as they hold structure and create pathways for air.

WATER – You want your compost pile to be moist, rather than wet or dry. The consistency of the bin’s contents should be damp like a wrung-out sponge.  Microbes struggle if their environment is too wet or too dry. They need water to live, yet too much moisture can limit the amount of oxygen they receive. If compost is too wet, it will start to smell bad. If this happens you need to add shredded paper and cardboard and aerate well so that moisture is absorbed.  

Add water to compost that is becoming dry by gently watering with a small watering can, preferably with rainwater collected in a water butt.

Adding food waste

Food waste can be added directly or in home compostable bags, never plastic. If you tie the bags, once you have added them to the Johanna make sure to break them open using the aerator stick to allow oxygen and microbes to reach the waste.

Add food waste and other Greens first, gently stirring these in with the older waste below.
This helps the micro-organisms working below to become part of the newly added materials.
Then cover with an equal amount of carbon materials (Browns) and gently stir again. If you
prefer you can premix these nitrogen/carbon materials before adding them to the bin. Finishing with a layer of carbon, such as dry dead leaves or shredded paper/cardboard, helps to prevent smells from food waste attracting flies and vermin.

The only food-related materials that are not efficiently digested by the Johanna are those that require a very long time to break down, such as bones, large amounts of cooking oil/fat, the hard shells of nuts and seafood (such as oysters and crabs) and avocado stones.

If bones are added to the Johanna they will not break down and it would be
necessary to remove stripped-down bones from the finished compost, which could present
a danger to dogs. For this reason we do not recommend that bones are added.

You can boost the breakdown process by adding bokashi bran (available separately), fermented waste from a bokashi bin, or a bucketful of mature compost.

The Green Johanna Insulating Jacket (available separately) helps to boost temperatures for hot composting and to maintain composting performance in colder weather for regular composting. It should be removed in hot weather or the internal temperature in the bin could become too hot for the composting creatures to survive (above 70 degrees Celsius).

And finally…

To access your finished compost simply unscrew the hatches at the bottom of the Johanna and remove the compost using the aerator stick or a garden hoe.

If you want to access larger amounts of compost that have been left to mature, you can unscrew and remove the Johanna’s top sections. Return any fresh organic waste to the reassembled composter to continue breaking down.

The Johanna was designed and originally manufactured in Sweden, but is now made for Great Green Systems in Droitwich, Worcestershire.

What will you do with that pumpkin?

Remember, remember, come the month of November,

Halloween brought fun and mirth,

But don’t let that pumpkin

Rot in a wastebin

When it could nourish the earth.

Don’t let your pumpkin lantern be one of those that contribute to greenhouse gases – compost it and feed the earth instead.

Along with all the tricks and treats, every year Halloween brings horror stories about how many pumpkins will end up in landfill or incineration. Around 15 -20 million apparently. Most of them haven’t been used as food first either. But it doesn’t have to be that way.

You could make an occasion of pumpkin disposal and go along to a Pumpkin Smash. These are organised events where people are invited to take their used pumpkin lanterns to be smashed up in a variety of fun ways and then composted, putting nutrients back into the soil.

Check to see if there’s a Pumpkin Smash taking place near you. If you live in Leicester you no doubt know about the popular Pumpkin Smash at the Stokes Wood Allotments site. These events are usually followed by a practical session on composting pumpkins and food waste in general. People are encouraged to also collect pumpkins from friends, schools or pubs to help reduce waste. The more the merrier – let’s smash a hole in that 20 million statistic!

 Let’s hope this great idea catches on and we see more Pumpkin Smashes all over the country next year.

A Pumpkin Smash is great way to teach kids about composting and wean them off the idea that wastebins are for everything.

If you use battery-powered tealights inside a lantern, the insides will be kept fresh enough to eat later.

 Don’t bin that pumpkin –

It’s better to get a Johanna!

A happy Halloween ending

To compost your used pumpkin, cut the skin into pieces (the cutters in Halloween lantern carving sets can be useful for this job) or use a spade to chop it up.

Get children involved by letting them add the pieces of pumpkin to a composter and stir in well together with woody garden waste, autumn leaves or scrunched paper and torn cardboard.

If you’d rather eat your pumpkin – yes, the whole pumpkin – this recipe’s for you.

We got it from Chef Dan at Kitche, the food waste fighting app. We tried and tested it and found it totally delicious.

ZERO WASTE PUMPKIN SOUP

Serves – 4

Time – 1 hr 30 mins

Ingredients

1 medium large pumpkin

3 large onions

3-4 garlic cloves,

Olive oil

1 litre vegetable stock

1 can coconut milk (optional)

Sprig of rosemary

2 bay leaves

Salt and pepper

Method

1. Wash, cut in half and gut your pumpkin, making sure to separate the flesh and seeds.

2. Crush garlic and finely chop the onions and add them to the pan, add oil and simmer until slightly golden.

3. Chop remaining pumpkin into large cubes and add them to a large pan with the pulp.

4. Finely chop your rosemary and add to the pan with your bay leaves, which you can leave whole.

5. Add your veg stock, making sure the ingredients are covered.

6. Add coconut milk if using.

7. Put on lid and let the pan come to the boil. Once bubbling, turn the heat down so the soup is simmering. Sort out the seeds while waiting.

8. The soup will take at least an hour to cook. Make sure the pumpkin skin is soft (this can take a little longer depending on the type of pumpkin).

9. Once it is ready, remember to take out the bay leaves and add salt and pepper to taste. Use a hand blender to make the soup smooth and creamy. Add water if required until it is your desired consistency. Can be stored in the fridge or freezer.

What to do with your pumpkin seeds?

The seeds make a great garnish. Lay them out on a baking tray and lightly salt them. They only take 5 – 10 minutes and burn easily. If you don’t want the seeds on soup, save them till spring and plant them in your garden.

***

 We also like this idea for pumpkin seeds from the organic online store Abel and Cole:

Give seeds a rinse, then toss in a little olive oil, salt and paprika and fry them for 5 minutes until golden brown – a great snack to serve at Halloween parties.

Spare Parts