Tips to deal with fruit fly nuisance

Fruit flies are a common nuisance in the UK, affecting more than 60% of households.    

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 is out of balance. 

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.
  • Other smells they dislike are: citronella, cinnamon, pine oil, tea tree. Also try planting (in pots or directly in the ground) basil, mint, rosemary, marigold, lavender.
  •  Try a cayenne pepper bug repellent spray – mix 250 ml of water and one teaspoon of cayenne pepper in a misting bottle and spray it around.
  • Try a lemongrass spray – 25 drops of lemongrass essential oil with half a cup of hot water.
  • A tip we’ve come across but not yet tried: hang up a bag containing coins (or pieces of aluminium foil) in water – the coins reflect sunlight which dazes and deters flies as their eyes are sensitive to light changes.
  • 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).

Green Cone still going strong after 25 years

Although a Green Cone is expected to last for at least 10 years, customers often report their Cone has lasted a lot longer than this.

The oldest Cone that we’ve heard of belongs to a lady in Scotland, who got it through her local authority, Argyll and Bute District Council, 25 years ago.

The customer’s daughter contacted us when the Cone’s lid blew off in a storm and Great Green Systems replaced it free of charge.

 She said: ‘The Cone is still going strong, a real asset in a rural area where there is no specific collection of food waste. ‘

Another Cone going strong, and coping with extreme heat, is one that was taken to Spain by its owner, Angela, nearly 20 years ago when she bought an old Spanish farmhouse.   

Angela knew the Cone worked well at home in England so it would be an even greater asset in Spain, with heat, foxes and rodents to contend with. The family took their Cone over to Spain in their car.

‘We love our Cone and it is really, really useful,’ says Angela.  ‘I must say that we have been surprised and delighted that the actual Cone has lasted brilliantly all these years. We wouldn’t want to be without it.’

For several years the family made annual trips to their Spanish house, spending working holidays getting the house and garden ready for their eventual move.

On one visit a big family birthday was celebrated with 10 guests staying for a full week. The Cone’s underground basket (which is where food waste lands) was full after the week, but when the family returned months later they were delighted to find that the basket’s contents had almost completely vanished.

A long reign in Spain – Angela’s Green Cone outside her Spanish farmhouse.

The family relocated to Spain a few years ago and over the years Angela has seen big changes there in attitudes to recycling food waste.

She says: ‘Things have become easier over the past few years as Spain has started to install special organic recycling bins, which have a swing top and drop waste into an underground receptacle that is then cleared very regularly by the council.  

A good ecological cycle

‘So, from nothing less than 20 years ago, we have multiple ways of safe and hygienic organic waste disposal, the most convenient of which is our Cone.

‘To be honest, it is as much of a pleasure to take the bin out to the Cone as it is to go out and pick veggies for supper because it is useful to process things ourselves and know that we are using a good ecological cycle for production and waste.’ 

The couple grow a lot of their own produce and have had to contend with many challenges posed by the climate and mountainous geography. Their Cone has been moved four times, with placement being determined by where there is sufficient depth to site the basket, which needs to be embedded in soil.

‘When there is torrential rain and it floods over the terrace behind our land it can remove soil down to the bedrock, it was quite a shock the first time we saw this and realised just how little soil covering there is in some places,’ Angela says.

‘As a consequence, we have built raised beds for some of our produce and will be looking to make deeper beds for some others as time goes by.’

A 5000-litre tank for rainwater has been an essential investment.

Angela says the Spanish are becoming much more interested in tending gardens.

 ‘People have been quite interested in our approach (raised beds, adding marigolds for insect control and so on). Possibly they will become more interested in composting as well since many areas have banned burning of waste, partly as a fire hazard and partly air pollution, so things are changing gradually.’

How to get the most from your Green Cone

The Green Cone’s basic needs are:

  • A sunny spot
  • Well-draining soil (not clay or chalk)
  • Additions of food waste – no garden or paper waste
  • Accelerator powder to boost digestion
  • Food waste should never come higher than the underground basket into the Cone itself

Where shall I put my Green Cone?

As well as finding a sunny spot, it’s a good idea to think about how easy it will be to get to the Cone in winter months to empty your kitchen caddy.   

More than 90% of the waste added to the Cone will be turned into water, which must be able to drain freely away for the unit to work properly, so the Cone needs to be embedded in soil that has good drainage.

How do I know if I have good drainage?

If you’re not sure whether your soil has good drainage or not, you can check by doing the following: dig the hole required for the Cone (about 70cm wide by 54cm deep) and pour a bucket of water into it. If the water remains for more than 15 minutes you have poor drainage and will need to enlarge the hole to 90cm wide by 70cm deep.

Provide extra drainage by mixing soil from the hole with gravel, stones, or small pieces of broken bricks and pots and placing some of this mix in the base of the hole so that when the assembled Green Cone is added the basket sits 3cm below ground level. Then use the gravel/soil mix to backfill gaps around the Cone until the bottom rim of the green outer cone is fully covered.

How do I look after my Green Cone?

Basic maintenance involves ensuring that the Cone’s green rim always remains below ground level.

In the first few weeks after installation check that soil has not settled and left the green rim exposed. This could also happen after heavy rain. If this is the case, make sure to add additional soil and compact it around the Cone to keep the rim securely underground.

How much waste is too much for the Green Cone?

Remember that food waste should only ever be in the underground basket: never allow waste to build up so that it is above ground level inside the Cone itself.

The Cone is expected to cope with the food waste produced by the average family of four, but this can vary greatly. If you find you regularly have more waste than the Cone can cope with you may need another Cone to cope with all your leftovers.

If you find that in autumn and winter the digestion process has started to slow down and the waste in the basket doesn’t appear to be reducing, simply add a little more accelerator powder.

Why the Green Cone is a bear necessity

The Green Cone was designed by an engineer in Canada to solve the problem of bears pushing over rubbish bins to get to food waste. While bear-proofing may not be on your list of requirements, the Cone is sure to deter local foxes.

If vermin are a problem locally, you can add additional deterrents by hardening the area close to the Cone with bricks or rocks and by positioning the Cone away from fences, woodpiles and bushes.

If pet waste is to be added to the Cone, the unit should not be placed in soil where vegetables are grown or close to any water source. Pet waste should only be added  in small amounts and never in bags.

No bags of any kind should ever be added to the Cone as this will hamper the digestion process.

Why our Green Cone was a very good buy

Before buying their Green Cone in 2009, Jack and Joan Milner, from Leicestershire, thought the prospect of being able to safely dispose of all their leftovers sounded almost too good to be true.

‘We were a bit sceptical at first,’ admits Jack. ‘We had already tried having a compost bin but we were not systematic enough to make it work.’

But at the time Leicestershire County Council was offering residents subsidised Cones to encourage them to recycle food waste at home instead of sending it to landfill. So the couple decided to give it a try.

A place in the sun

Under the scheme at the time, the council arranged for Green Cones to be installed on their residents’ behalf since the units must be dug into a hole in the garden.

 Once this was done, and the Cone was in place in a sunny spot near the kitchen door, the Milners began to feed it their leftovers, including bones.

‘It wasn’t long before the Green Cone was called ‘George’ (don’t ask us why!) and we fed him daily,’ says Jack.

 A pleasant surprise

The couple, now in their eighties, were quickly won over by George’s powers of digestion. ‘We have been very pleasantly surprised.’

Jack and Joan sometimes have to deal with the common problem of visiting dogs and cats leaving a little deposit on their lawn, but ‘George’ has even been efficient at dealing with this.

Most of the waste deposited in the Cone breaks down to become nutritious water that drains from the underground basket into surrounding soil. The Milners have noticed the effect of this soil conditioner on their garden.

A very good buy

Their Cone was placed in an arid spot which sported a few Lily of the Valley flowers and these soon began to flourish, becoming ‘a superb patch two metres in diameter.’

Jack adds that their Cone is now becoming a bit brittle but still ‘completely serviceable’, and it is only now after 13 years that it might need emptying.

‘Overall, George has been a very good buy.’

What’s in a name?

Incidentally, the Milners are not the only customers who have found themselves giving a name to their food waste digester. In our reviews section is a family who named their three Green Johanna Hot Composters Bertha, Belinda and Beryl. Whatever you may wish to call your Cone (and names are not obligatory, we don’t check!) we’re sure life with your own George, or Daisy or Engelburt will be just as good as the Milners’ experience.

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