Which composter is best for me?

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.

Waking your compost bin in Spring

This is the time compost fans have been waiting for.  At Great Green Systems we leave our compost ‘cooking’ for two grand occasions a year – April and October – for the Spring and Autumn retrieval of mature compost from the Green Johanna.

If you’re a first-time user of a Johanna, we recommend waiting 6-8 months before taking your compost out. After that, depending on conditions, 4-6 months should be fine.  

You can take compost from the bottom of the Johanna by unscrewing the hatches and removing compost using the aerator stick or a garden hoe.

To remove larger amounts of compost that have been left longer to mature, you can unscrew the Johanna’s modular sections, then remove materials from the top that are still decomposing and place them on a tarpaulin to enable you to get to the mature compost. Then put the decomposing materials back into the reassembled compost bin to continue breaking down.

Taking a Green Johanna apart to take out compost

Compost is ready when it looks like soil – dark and crumbly – and also smells like fresh soil. There may be some items that have not fully broken down, such as sticks, bits of eggshell and tea bags. These can be taken out and put back into the composter to go through the breakdown process again.  If there are other recognisable waste items and an unpleasant smell, the compost is not ready and should be left to continue breaking down.

This is also a good time to take leaf mould out of composters that are used only for leaves for use in your compost mixes.

Leaf mould taken from a Graf Thermo King 900 litre composter after two years breaking down

Use your compost for:  

Planting – Compost acts like a natural fertiliser enriching the soil and helping plants to thrive. As it is taken into the soil by worms and other organisms, the compost feeds plants and micro-organisms in the soil. For different compost recipes, check out the Garden Organic website – www.gardenorganic.org.uk.  

Mulching – At the beginning of the growing season mulches warm the soil, helping it to retain heat which would be lost at night.

  • Mulch also creates a haven for insects and worms which in turn attract birds and other wildlife, creating a mini eco-system in your garden.
  • Gardeners appreciate the neat weed-free appearance that mulch creates.
  •  If you have a dry garden, you’ll be glad of the protection that mulch offers plants in retaining water and cutting down on evaporation. This means you don’t have to water as frequently. Apply mature compost on soil after a spell of rain to retain moisture. Lay the layers at least 5cms thick after first removing weeds.

Planning your planting

  • Choose plants that peak at different times from June through to September.
  • Check the eventual height and spread of each plant before you plant it.
  • Water in each new planting and keep them watered regularly during their first summer.
  • Tackle weeds – the best approach is little and often. Hoe once a week to dislodge annuals. Perennials can be pulled out by hand if they’re still small, or if larger they can be dug out with a trowel.  
  • If you want to embrace No Mow May, allowing wildflowers to flourish and creating a habitat for insects, but you’re worried your lawn will look too wild, compromise by mowing a path through the grass and neatening edges.
  • Support Peat-free April – although the UK government has banned the sale of bagged peat for home gardeners, peat is still used for growing plants to sell. Support peat-free nurseries and suppliers by going to the Peat-free April website (www.peatfree.org.uk)

Tips from the experts

Sarah Raven is surely the Queen of Pots – she has 382 pots in her garden. In her book A Year Full of Pots (Bloomsbury) she advises:

  • Keep your eyes peeled for pests as the weather warms – deal with aphids with a jet of water from the hose.
  • Label everything because it’s easy to forget what’s what. Always start writing at the blunt end of your label.
  • If you don’t have a polytunnel, greenhouse or cold frame, it might be easier to buy seedlings online rather than sowing everything into trays and filling your windowsills. Perhaps select one or two to sow, ones that you know are easy, and buy the rest as young plants.
  • The commonest method she and her team use is the seed tray method – using peat-free potting compost, they place everything on a heated propagator mat. Warmth helps to speed up germination, so keep bags of compost inside if you can. Water the compost in the trays with watering cans that have sat on the hot bench.
  • Storing seed – if you have any leftover seed, secure the packet and put it in an airtight box. Store somewhere cool until next year.

Poppy’s plants

There may now be enough light for tender plants to grow outside but is it still too cold for them?

Poppy Okotcha, writing in her Observer gardening column, uses the rule of thumb that if it’s chilly outside for her and she needs to wear more than a T-shirt, then tender plants are probably feeling the cold too. She advises:

  • A sunny windowsill, warm conservatory or porch will do them well until the frosts pass and day and night temperatures consistently reach 8-10 degrees C.
  • It’s worth finding out the hardiness rating of the crop you’re sowing so you can cater to its needs. After the seeds have germinated, any hardy seedlings can be relocated somewhere with plenty of light that is not too warm. A cool, bright windowsill, conservatory, porch, or cold frame would do, or for those lucky enough to have one, an unheated greenhouse is fine. If seedlings have too much warmth and not enough light they will grow ‘leggy’, which just means spindly and weak.
  • Source seeds that are ethically grown, such as those certified organic by the Soil Association or Biodynamic by Demeter.
  • Keep tender plants safe from slugs and snails through Spring by covering them with cloches, plastic bottles or glass jars to act as physical barriers until the plant is vigorous enough to withstand some nibbling.  Put the containers on in the evening and take them off in the morning.

Let’s not forget wildlife

Remember visiting creatures when you’re out and about in your garden.  

  • Leave natural materials outside for nest-making.
  • Create resting places for bees just waking up.
  • Plant quick-growing flowers for pollinators.
  • Deep clean any bird feeders and baths.

Compost your way to a peat-free future

The long-awaited ban on sales of peat-based compost comes into effect for home gardeners this year.

This isn’t the end of the story, however. For the professional sector, a phased approach will reduce use from December 2026 before a full ban comes into effect from 2030. This means that while some peat-containing products will be banned from shelves in 2027, others will be exempt until 2030.

The gardening charity the Royal Horticultural Society (RHS) encourages gardeners to take the matter into their own hands by making their own compost, as a free, easy and sustainable alternative to shop-bought soil improvers.

Professor Alistair Griffiths, Director of Science at the RHS, says: ‘Composting is one of a handful of small changes gardeners can make on their plots to help accelerate the UK’s transition to peat-free and for people to make a positive difference to the environment and the health of their plants and planet.’

The charity Garden Organic believes that if consumers are provided with the facts they will swap their peat-based compost for homemade or peat free.

It has long campaigned for the end to peat use through its For Peat’s Sake campaign and is committed to getting the word out to as many people as possible through gardening clubs, allotment associations, garden centres and schools. To join the campaign, go to Garden Organic – Discover organic growing  The website also has guidance on making your own peat-free compost mixes.

A long story

It’s been a long and winding road to get to this year’s ban and there is still wide-spread confusion.

In 2011 an agreement was reached between the horticultural industry and the Government that the use of peat-based compost would be gradually phased out by 2020, giving manufacturers time to develop good quality peat-free alternatives.  This was a voluntary agreement, but the Government said it would legislate if this was not successful.

 The 2020 deadline was missed, so in August 2022, Defra (Department for Environment, Food and Rural Affairs) announced a ban on the sale of peat and peat-containing products in the retail horticultural sector by the end of 2024.  Consultations carried out with the public showed support for going peat free. Of 5,000 people interviewed, 95 per cent were in favour of ending peat sales to gardeners.  

Then last year the decision was taken to delay the ban for the professional sector until 2026 (with some exemptions) before the full ban in 2030. Defra said the delay was to enable professional businesses to find other suitable peat-free growing alternatives. It said a balancing act was needed between protecting precious peatlands while also acknowledging difficulties faced by the industry in making the changes.

Peat-free alternatives include organic materials such as bark, coconut fibre (coir) and bracken.

With more than 7 million people having taken up gardening since the pandemic, demand for compost is greater than ever.  The amateur sector accounts for 70 per cent of sales of peat-based compost in the UK.

Why are peatlands precious?

Peat is an accumulation of partially decayed ancient plants in the earth’s wetland eco-systems, called peatlands or peat bogs. Because it is stored under water, the organic matter doesn’t release carbon as it decays. Many of these peatlands have been growing undisturbed for thousands of years.

The UK’s peatlands store three times as much carbon as its forests, but the vast majority are in a degraded state.  Estimates suggest that only 5-10 per cent remain in near-natural condition.

For peat to remain healthy it must remain wet – extraction dries it out, sometimes triggering wildfires, and the carbon inside the bog is released as carbon dioxide, accelerating climate change.    Emissions from peatlands make up over 4 per cent of all the UK’s annual greenhouse emissions – the equivalent of the carbon footprint of just under 2 million people.

With extraction, wildlife also suffers as animals lose their homes, and the local area loses a defence against flooding as healthy peatlands act as huge sponges.  

The extraction of peatlands was scaled up in the early 1960s for the horticultural industry. For decades it has been an ingredient in the majority of composts sold in British garden centres. It became popular as a fertiliser because it retains moisture and nutrients. It’s also inexpensive and easy to dig out and process into bags.

Environmentalists have long warned than digging up peatlands for use in gardens is a huge source of emissions and devastating for wildlife. The conservationist David Bellamy raised the issue of peat bog damage in the 1970s. Globally, peatlands store half a trillion tonnes of carbon. Environmental agencies say that any peat compost ban must include the importation of peat in potted plants.

Monty Don, presenter of BBC’s Gardening World, has said that using peat is ‘eco-vandalism’ and there is never any justification for using it.

When the delay to the ban was announced, Garden Organic expressed disappointment, not only at the delay but also the confusion that had been created.

Garden Organic’s chief executive Fiona Taylor said: ‘Peatlands are running out of time, and we need action now to stop the degradation of this precious eco-system just for the sake of our gardens and garden plants. Gardening should be about giving back to nature, nurturing plant diversity and soil health.’

She said the delays created a confusing marketplace for gardeners trying to do the right thing.

‘It’s good that gardeners won’t be able to buy bagged peat from 2024, but at the same time they could be buying it unwittingly via shop-bought peat-grown plug plants. ‘

Exclusions to the ban include a special dispensation for plug plants and mushrooms, which together made up 42 per cent of all peat used by professional growers in 2021.

The Wildlife Trusts have also been urging governments to enforce bans for the last 30 years. They say the burden should not be on the consumer to ensure they are not inadvertently buying peat-based products.

Research by the RHS last year showed that fewer than one in five nursery growers were peat free, but some had moved to peat-free growing in every main plant group, showing that the shift was possible for all plants.

 Despite the delays, the UK is far ahead of other countries in tackling the issue.    

The benefits of quality homemade compost are many – when added to soil, compost sequesters carbon, improves plant growth, conserves water and helps prevent nutrient runoff and soil erosion. Used as a mulch added in layers of 5cm on the top layer of soil, it suppresses weeds, improves soil structure and prevents moisture loss in hot weather.

And if you’re anything like us at Great Green Systems, composting can become a fascinating hobby too.

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 facts unearthed by Dr Stuart Farrimond, in his book The Science of Gardening.

Dr Stu is a medical doctor turned science writer whose books explore the science behind everyday life.

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

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 also 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.

Here are a couple 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.

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

Should you sweep or leave those leaves?

Sometimes you think you’re doing the right thing, only to find out that maybe you’re not.

I’m thinking of autumn leaves and what we should do with them.

Our family came to composting the easiest way, through making leaf mould – fallen autumn leaves that are left to rot down. Our garden receives an abundance of leaves every autumn, as it’s home to a horse chestnut tree and overlooked by several other trees. We soon got out of the habit of paying the council to take away bags of leaves as the cost mounted. So we got two 900L Graf Thermo King composters and started making leaf mould.

But once I realised what a fantastic resource leaves were (they build soil and store carbon), I couldn’t bear to see them lying around all over the place going to waste. I read about what sounded like a great solution – eco-warriors all over the world who sweep the pavements in their neighbourhoods to collect leaves for composting. So I joined in.  

Pollution

Then I read something else – that you shouldn’t sweep busy streets because the leaves could be contaminated with pollution from traffic fumes. That made sense, so I started to sweep leaves from grassed areas (after getting permission).

Then I read that you should leave the leaves on soil and around trees and hedges as they replenish the soil with nutrients as they decompose, providing food throughout winter. Apparently removing leaves contributes to the slow death of trees from malnutrition. Aaaargh!

At this point my husband suggested that I stop reading.

Ignoring him, I read somewhere else that leaves are low in nutrition because all the nutrition is absorbed back into the tree before the leaves fall. As Homer Simpson might say, Doh!

Autumn glory – leaves left around the trees at Yorkshire Sculpture Park, Wakefield.

I remember last year the Royal Horticultural Society advised people to leave autumn leaves on borders as they encourage worm activity and increase humus content in soil. But then others piled in to say that leaves have an annoying tendency to not stay where they’re put, with the wind teasing them out and repositioning them on the lawn or, dangerously, the garden path. And in our case the hallway too. So what to do?

Ideally you should only collect leaves from hard surfaces as they would otherwise only be blown or washed away by wind and rain. But you should rake them off lawns and plants to prevent them smothering growth.

 The solution I came up with is to go to alleyways (or ‘ginnels’, if you come from Yorkshire) where there is no traffic so no fumes and no soil/trees needing to be fed over winter. On pathways leaves are wasted and the only thing they create is a slip hazard. You just need to watch out for hidden dog poo, but as dog lovers we’re used to that.  

Gathering leaves that would go to waste

We have now taken to wrapping our garden tree with a rich leaf-blanket, or bug rug as I call it. If the leaves are dry they will blow away so we dampen them with rainwater from our water butt to weigh them down a bit.

Left leaves also create a habitat for insects, beneficial bacteria and pollinators. Soil apparently needs more winter cover than you might imagine – not a stingy couple of centimetres, but a big generous serving. As well as feeding the tree it will also protect the roots from weather extremes.

As a proud member of the Earthworm Society of Britain, I was interested to read about the Leave the Leaves Project, which will investigate the benefit of leaving leaves in London parks, comparing the earthworm population in areas that are cleared of leaves and areas where the leaves are left to be dealt with by earthworms. Volunteers can register via The Royal Parks website.

The rake’s progress – making a ‘bug rug’ for around trees

Storing leaves for compost

Stockpiling autumn leaves for composting ensures you have readily available Browns to balance the Greens. While food waste is usually plentiful, providing you with Greens, finding more carbon-rich Browns content can be harder.

 Shredding the leaves increases the surface area in contact with microbes, speeding up decomposition. Shredded leaves also take up less space if you don’t have much room to store them and they’re also less likely to mat down in a bin, excluding air from the compost.

 If you don’t have a shredder, you can mow over them; set your mower on a high cut setting and mow them up, using the grass collector added to the back of the mower. You can also whizz them up with an edge trimmer in a dustbin (like using a food stick blender) or use a pair of hedge clippers and a board.

Rake leaves on lawns to prevent them smothering growth

Store dry leaves in old compost bags or thick black bags next to the compost bin so they’re ready when needed.  Then when you add a kitchen caddy of food waste you can add a caddy full of leaves to the bin, so providing the good balance of nitrogen and carbon necessary for efficient composting.

Some leaves break down more quickly than others. In his book A Gardeners’ Guide to Composting Techniques, Rod Weston says the leaves of common UK trees, such as oak, beech and hornbeam, break down comparatively easily to produce good-quality leaf mould, while horse and sweet chestnut and sycamore are slower to break down.

‘Conifer needles are slower still. They should be treated separately, in any case, as they produce an acidic material, which is ideal for mulching ericaceous plants.’

What are the benefits of leaf mould?

Leaf mould has similar properties to peat but has the benefit of being a renewable resource. Like compost, it will improve the structure of your soil and increase water retention by around 50 per cent. Fallen leaves are soil-building, carbon-storing materials.

How do I make leaf mould?

Making leaf mould is a simple but slow process, relying on fungi rather than the heat-generating bacteria of the composting process.

The most basic way of storing leaves is to keep them in a black bin bag, pierced at the bottom and sides to allow the contents to breathe.  If the leaves are very dry, moisten them with stored rainwater before putting them in the bag. You don’t need to add anything else – just the leaves, but adding some grass will speed up decomposition.

If you prefer a container, the Thermo King compost bins that we use make life simple because:

  • Two large flaps make it easy to remove compost.
  • The lid allows humid air to escape and is adjustable to summer and winter weather conditions to regulate air circulation.
  • The base (optional) allows worms and insects to enter while deterring rodents.

Check the leaves from time to time, especially during hot weather, to ensure the contents are still wet.

How can I use my leaf mould?

If leaves have been left to rot for two years or more, they can be used as seed-sowing compost or mixed equally with sharp sand, garden compost and soil for use as potting compost.

If less than two years old, leaf mould can be used as autumn cover for bare soil in winter. It looks and smells like compost – dark brown in colour and crumbly in texture.

In his book The Science of Gardening, Dr Stuart Farrimond points out that in nature nothing is wasted, ‘and all the soil nutrients upon which plants depend, including nitrogen, phosphorus, potassium and calcium, are replenished in forms ready for roots to take up. Far better than feeding your plants is to feed your soil and support this natural nutrient recycling system.’

Julie

Spare Parts