Mouse eviction! Or how to fix up an under-active compost bin

Probably the most common problem that can occur with backyard composting is attracting pests, particularly the rodent kind. The inside of a plastic compost bin is insulated from the elements and full of tasty treats so it’s easy to see why they are attracted to it. Another aspect of the average backyard composter is that although it may be a nice warm mouse house it’s not HOT, as in hot composting. Even if you regularly forget about those veggies in the fridge and end up wasting quite a few of them, or cook most of your meals from scratch it’s unlikely that you will generate enough nitrogen rich veggie scraps on a regular basis to start generating heat in your compost bin. This is true even for households of 5 or so people, including little ones who may generate more scraps in the form of half eaten snacks etc. Why does it matter if the compost bin gets hot or not? This determines how quickly the scraps break down. A handful of scraps thrown into a cold composting system may no longer be food safe for us humans but they can remain fresh enough to be attractive to mice and rats for weeks. Whereas a bulk amount of the same veggie scraps in a hot composting system will generate heat and in turn hasten the degradation even more by essentially cooking the veggie scraps. In a day or two they will no longer resemble veggies and the mice and rats will no longer be interested. They also may not find it so comfortable once the interior of the compost bin is up around 60-70 degrees Celsius!

cute! but preventing compost from being made

So besides wasting heaps of veggies (which would be a terrible idea for many reasons) what are you to do? Limit access and make it uncomfortable for the little thieves! The presence of mice or rats may also indicate a compost bin that is too dry. Nothing will break down to any great extent if there is not enough water. All of the bacteria and fungi that do the hard work need water to survive, after all. Don’t just flood the mice out though, as too much water in the compost will also slow things down, and produce bad smells along with methane and other greenhouse gases.

When a HCC contributor sent me the above photo it was easy to suggest a course of action. Peter does the right thing and sends the really tasty kitchen wastes like bread crusts and leftover rice to the HCC, but composts most of the vegetable waste in his own bin. If you’ve ever heard anyone say ‘you can’t compost bread’, what they actually mean is ‘bread is great in compost, it breaks down easily, but unless you have a pest proof system then you’ll end up attracting mice/rats as they love the stuff’. Peter’s heap must not be completely pest proof yet. It’s surprising how small of a hole mice can fit through. Someone once told me they only need about a square centimeter to squeeze through. The best way that I’ve found to keep them out of a plastic composter is to ensure that the base is impenetrable with a few inches of soil piled up against it. Just like making a sand castle, just pile it up around the base of the unit and pat it down to compact it slightly. Yes, the critters can technically still dig through, but they are more likely to run off and investigate other options before they bother.

You can also make the scraps inaccessible from the top (in case they’re running up the sides and squeezing into a lid that’s slightly ajar, for instance). If there are lots of tasty scraps in the bin, you can cover them all up with, what else? compost! The HCC ‘semi-compost’ is perfect for this. ‘Semi-compost’ is what I have started to refer to when there is a pile of material that has cycled through the compost bays yet still needs to break down quite a bit.

the pile in front is ‘semi-compost’, the pile in back is just leaves!

And while you’re adding semi-compost why not heat things up a bit? For Peter’s heap I supplied a nice big bag of coffee grounds, as well as a pile of semi-compost. The idea is to add a nitrogen source that will speed up the decomposition of the whole. Watering this in is a good idea, especially if the pile is dry, but also to distribute the coffee grounds down through the existing mass. Then the whole lot can be topped off with the semi-compost, which the mice won’t be inclined to dig through to get to the tasty bits and will also inoculate the heap with good bacteria and fungi. You can also use grass clippings or a thin layer of manure for a nitrogen rich boost. Finally, (and perhaps waiting a day for the mice to vacate), build your ‘soil moat’ around the base, packing it up against the composter walls to secure the perimeter. Easy peasy! I would then let this whole lot sit for a few weeks, and then turn the whole lot over.

coffee grinds (as shown with portafilter), followed by water and a nice big pile of semi-compost and the mice will vacate! Pack soil around the base for extra reinforcement

If you have a compost bin in a similar situation I’d be happy to supply the semi-compost and even do all the hard work for you. All with the aim of diverting more kitchen scraps from landfill! I would ask for a donation to keep the HCC chugging away. If you think it’s worth it to keep the scraps out of landfill (and to not expand the rodent population) then you can enquire at hacketcompost2602@gmail.com.

-Brook

 

Sharing the bucket love with a far-reaching network

Door to (back)door delivery – HCCers meet Marie-Helene

The ‘Hackett’ Compost Collective is a bit of a misnomer because you don’t have to be a Hackett resident to contribute! The name is there as more of a legacy and also a reminder that community composting works best on the local scale.

Contributor Marie-Helene shows us all that the HCC can help reduce waste to landfill not only in our own homes but by allowing others to be involved also. Marie-Helene has been a HCC member since last July when she heard all about the HCC in the SEE-Change newsletter. At the time she was living in North Ainslie. I was more than happy to take a small detour off the bike path to pick up her bucket of scraps on a regular basis. Since then, something drew her to move to Hackett. Funnily enough it was around the same time that another HCC member (Caitlin in Lyneham) moved to Hackett also! I’ve always had in mind expanding the HCC to other suburbs but I didn’t imagine that other suburbs would come to us!

Marie-Helene actually keeps three buckets on hand, one for the kitchen bench, a larger one outside that she empties into, and a third that she takes to work. She’s noticed that the small amounts of organic waste generated in the work place, from coffee grounds to banana peels, add up. And while a banana peel here and there might not seem like much the small bucket has been appreciated by many. Indeed, while Marie-Helene was moving house she took a break from scraps collections (understandable!) but her colleagues, including her director, missed the opportunity to send their waste somewhere worthwhile. Marie-Helene is settled into Hackett now and the three bucket system is working great.

Scott and I also take buckets to our workplaces to get them filled with goodies. In Scott’s case he works with lots of younger people living in apartments so it’s not unheard of that he is bringing home 4 or more buckets full of scraps in his bike panniers on any given day. All of these HCC contributors are valued. And like Marie-Helene, all of them feel better knowing that their scraps are not ending up in landfill. A win-win all round!

Marie-Helene is originally from Canada and she’s certainly not afraid of a little weather. As a side note: I love getting the perspective from people from different climates, to think that I used to hold off on riding my bike if it looked like rain! So it didn’t bother her at all that she walked over with her full buckets during the wettest part of this Queen’s birthday holiday (the skies are clearing now as I write this). It’s fantastic when people in the same local community can help each other out. In the same way, Marie-Helene would like to get her own compost heap started and I’d love to help with that. As Marie-Helene and her family live in a unit she needs to arrange permission with the body corporate first. After all, there can be concerns with pests and odours when it comes to composting. But with proper management it really is the best way to manage our wastes and turn them into something wonderful. At the very least I can share some semi-composted materials with Marie-Helene to serve as ‘activator’ in a new heap, as well as plenty of tips for a productive heap. In the meantime we’ll keep the full and empty buckets circulating, and anyone is welcome to help us fill them up 🙂

-Brook

HCC is all about good community vibes

Howdy HCCers, I’d like you all to meet Ingrid in Downer who has some lovely things to say about getting involved with the compost collective:

“Hi, I’m Ingrid and I have been part of the HCC since February 2019, after delightfully stumbling across a poster for the HCC at my local Downer cafe!
I moved to Downer last year and was struggling to figure out what to do with my kitchen waste. I’d grown up with chickens and previously lived close enough to my parents to drop my scraps back to the chicken coop, but after moving further away this didn’t suit anymore. I am aware of some of the impact of throwing food into landfill where it doesn’t break down properly, and it felt awful throwing it away.
So my housemates and I started talking about getting a little indoor compost in our townhouse. In the midst of these conversations I came across the HCC, and was so pleased to find a good way to use our scraps and divert them from landfill, with the bonus of being able to connect with others from my new local area also interested in this stuff!
It has been so great meeting Brook and others at an HCC open day, and learning about the composting process and all the neat things we can do with the converted waste (like giving it to community gardens, local school projects and peoples’ gardens!).
While we may eventually venture into small scale composting ourselves, I so enjoy connecting with others and working together locally through the HCC. Thanks Brook for making it so easy to be a part of!”
I completely agree with Ingrid, it is great to meet others in our local community who already value diverting food scraps from landfill and are willing to put in a little effort to do so. Like all the folks who drop off scraps while walking the dog, thank you! Ingrid is willing to put in even more effort as she has offered to help me turn the heap occasionally 🙂 (which she already got a taste for at the last open day). This helps hugely, especially as turning the heap regularly helps to reduce the greenhouse gases generated by the heap, by re-oxygenating pockets that may have become waterlogged and anaerobic.
I’m a strong believer in all of the little actions adding up to a significantly more climate-friendly lifestyle but it can be difficult when people don’t understand why you’re doing things the seemingly harder way. But ‘finding your tribe’ of like minded folk who can see the value in certain efforts can work wonders in keeping up the motivation to do the good work that you know will make a difference. In a similar vein, I finally went along to a Boomerang bags sewing bee the other weekend, something I’ve been meaning to do for ages. How many times have you heard people say ‘I know I should use re-usable shopping bags, but I just can’t remember to bring them to the shops’. Forming new habits can be really hard, even if you think it’s something you really want to do. Boomerang bags is now a world-wide community of people helping out of the goodness of their hearts to provide free to use re-usable shopping bags to help get you into the habit.
this is actually my first time ever using an interlocker, and it was heaps of fun!
Hopefully the HCC is also making it easy for people to get into the habit of separating out their food scraps and sending them to a better place!
Thanks very much Ingrid for helping me out and getting hands on with the heap. If anyone else wants an upper body workout feel free to enquire at hackettcompost2602@gmail.com
-Brook

Compost superstars and the ongoing barrel experiment

Yesterday I paid a visit to long time HCC contributors, Chris and Leigh in Gunghalin. But isn’t Gunghalin outside of the HCC collection area? That’s true, but Chris and Leigh happen to be very good friends of mine so that makes it easier for me to collect their kitchen scraps regularly. Also, Leigh had been working in Hackett for the last few months so she was able to drop off their scraps once a week. However Leigh will be taking a break from her paid work for the next little while as they are about to welcome baby no. 2!

Some people bring some nice biccies when they visit, I bring a big black bag of leaves

Despite impending life upheaval they have been very gracious and let me run a little experiment in their backyard. Chris and Leigh have been the first household to host a barrel. They found that the barrel could be tucked into a corner of their courtyard quite easily, in a convenient location that wasn’t too far from the back door and kitchen. Apparently little A is right into the spirit of things and is quick to declare “into the compost!” with any scraps after dinner. Chris has noted just how many half-eaten foods can pile up with a toddler in the house. With the scraps collections however, (either into a bucket, or into the barrel) they don’t have to take the kitchen bin out as often, a small win for convenience.

Family of four with a barrel and plenty of dry leaves tucked in behind the lemon tree

Although the courtyard is only small there is plenty of room to roll the barrel just outside their back fence. I’m sure the grass at the golf course doesn’t mind a little bit of nutrient rich barrel juice!

Chris and Leigh did a great job adding a handful of leaves each time they added kitchen scraps. The barrel had been gradually filled over three weeks. I was a bit worried that it might get too full and then I wouldn’t be able to lift it but it seems as though my initial estimate of a month was about right. I could have waited one more week before swapping it over. Nevertheless, I switched it with a clean barrel because I was keen to see how the decomposition inside was progressing.

plenty of leaves = no slimy mess

My one mistake was providing leaves that were still attached to twigs! The leaves had come from a pile that a neighbour had conveniently raked up yet there were too many twigs and sticks hidden in with the leaves. This just meant that it was a bit of struggle to get the contents of the barrel out.

Besides the sticks the contents of the barrel were great, no bad smells and it had obviously been hot enough to keep quite a few soldier fly larvae happily chomping away. It was certainly starting to compost and will integrate into the main heap nicely. I’m calling this a success! If you’d like to contribute scraps to the HCC but are not in the collection area, or don’t want to drop off scraps every week then a barrel could be a good option. Email Brook at hackettcompost2602@gmail.com if you’re keen 🙂

phew! emptied. I’m glad I provided nice small leaves for better mixing and less tangles this time!

Trike trial!

Howdy HCCers, meet Peter (he’s the taller one):

Peter and his family have their own compost bin but have also been contributing scraps to the HCC for quite a while now. Peter has also donated some large bags of leaves, keeping the HCC well supplied with carbon rich materials. But for the best contribution of all, Peter is helping to make the HCC carbon neutral (finally!).

Saturday is the main day for bucket swaps, and I have been driving around Watson and Downer to collect buckets of scraps on Saturdays for a while. At first I justified it because I would tie it in with collecting juice pulp from the farmers market. But what I really wanted was to be able to do the bucket run using pedal power. For that I needed a cargo bike. I started looking into cargo bikes and quickly learnt that a Christiana cargo trike would suit my needs, with an extra large bucket for carrying lots of buckets of scraps. Funnily enough I had been walking past one of these exact bikes each time I swapped buckets at Peter’s place but it took me a little while to realise that was the same model I was researching online! Better yet, when I asked Peter about it he told me he would be happy to sell it as his boys were outgrowing the kids seats it was originally bought for.

The Christiana cargo trike is all human powered (although it may be possible to fit a motor), so I needed to try it to see if I could collect all of the buckets under my own steam. Peter was very gracious and let me take the trike out yesterday morning, all around Watson and Downer, picking up buckets. Below illustrates how the trial went in pictures:

All loaded and ready to go
Hooray for shortcuts!
Although not all shortcuts were so easy…
Being on a bike lets you appreciate your surroundings more

perhaps you can tell by my expression but this hill in Watson did me in!

Made it back, with all the goodies

Basically, it was a very pleasant way to collect buckets of kitchen scraps. Much more fun that hopping in and out of a car. I was initially worried that I would annoy some drivers by taking up more of the road and being slow. But by the end of the ride I was much more confident and could easily slow down and pull left if need be. It helped that I went out quite early so that there wasn’t much traffic at all when I first hit the road. The total route did take me longer than in the car but that was partly because I kept stopping to take photos! (and to check the map a few times to verify shortcuts).

So, will I do it again? I sure will! The trial run was so convincing that I bought the trike off Peter the same day. I’ll look forward to taking it out again next weekend. I might just change the route slightly so that I go down Negus crescent rather than trying to push up it!

Many thanks are due to Peter to making the transition to carbon neutral bucket pick ups so easy. I thought I might have to go far and take much more time testing out and finding the right solution but luckily there was this great option right in Hackett 🙂

Heap refresh and new leaf store

They say change is as good as a holiday. In this case it was the main compost heap that got a holiday, while Scott and I got a work out.

Seeing as the wooden composting bays were getting a bit of a rest recently I took the opportunity to move the whole structure, just to refresh it. While the old location of the composter in the backyard was very convenient I decided to swap it with a raised bed on the other side of the garden that was having some issues. Roots from the nearby Birch tree had aggressively invaded the raised bed. Also, the metal wall of the raised bed has been getting the hottest afternoon sun. As a result the soil in this bed was not able to retain any water, so it was no good for growing veggies in. After emptying the bed of soil (no small task) I crossed my fingers that the metal ring forming the wall of the bed wasn’t concreted into the ground and then rolled the whole thing away.

Then we could empty out the wooden bays and move them across the yard. Easily done! (actually, as the wooden bays were initially built in place we didn’t know if this would be possible at all, with just two of us and a hand trolley. Luckily it all worked out and nothing at all was broken!)

Underneath the heap was a thriving community of decomposers, including some worms that I’d transferred over from the worm farm at one point. The worms don’t really like the middle of the active heap as it gets too hot for them but they’d obviously found a nice damp spot underneath the bays. Evidence of their action was some lovely castings that will enrich the soil beneath.

The wooden composter had been placed on some pavers so that it was not in direct contact with the soil. Nonetheless, seeing as the bays continually hold a warm, moist mass of decomposing organic matter it was expected that some of the wooden structure would be rotting. Also, areas where the paving stones do not make full contact with the wood will hold a little water and this will lead to wood rot also. This was mostly seen in a couple of supporting beams that brace the bays, so Scott quickly replaced a few of these. We’re happy for the structure to slowly break down though! I’d say the structure has at least another 12 months in it before it will be too wobbly and no longer pest proof. If anyone has some untreated 2 by 4’s that could be recycled to make the next one that would be tops.

Once we’d cleared the raised bed from it’s spot we realised there was more paving than we thought underneath it. This could be a great spot for a little tree! We tucked the composter behind this paved circle, nestled under the bottlebrush tree and installed the raised bed in the slightly shadier spot near the back fence.

Now full of layers of compost and soil
good spot for a citrus tree?

All the hard work of digging out soil and moving a very heavy wooden composter was carried out the weekend before last. Recently I started adding scraps to the bays once again and it seems to be composting quite nicely.

back in business
freshly turned as of yesterday, and actively breaking down loads of autumn leaves already (with the help of lots of veggie scraps)

The veggie bed in its new position might be a bit deprived of light over winter. At first I thought I would just sow some green manure on top of it. However, it occurred to me that it might be better used as a leaf store. I was inspired while digging decomposed leaves out of the gutter. Maybe that’s as grubby as it sounds, but there was a pile of leaves that had been sitting untouched out front of a neighbours place for about a year. The material at the bottom of this was a rich, organic soil that had formed as the leaves gradually broke down in place. The leaves that I store in the shed don’t have much opportunity to turn into this great stuff as they are protected from the weather. The new leaf store will be open to sun and rain and in contact with the soil too. I hope to fill it to the top of the chicken wire soon, and then let it sit to see how much of it transforms.

So if you see a lady in the gutters of the streets around Hackett, rake in hand, that’ll be me!

-Brook

Compost in barrels – composting in barrels?

What is compost anyway? Can you throw some veggie scraps and dry leaves in a barrel and call it compost? Will appropriate composting processes occur in the revolutionary new composting device that is a barrel with some holes drilled in it?? The answers to all these questions and more below (sort of), but first I’ll update on what’s been going on around the HCC heap.

Some people might tell you that composting is easy and compost doesn’t smell. While those things are true, they come with some caveats. I like to keep this blog light and to celebrate all the good things coming out of the HCC but it’s not always sunshine and things smelling like roses. On and off this summer the HCC heap has been releasing some unpleasant odours and my poor neighbours have been bearing the brunt of this. This is a very serious issue and I need to manage it otherwise the HCC heaps will need to relocate. That’s not good as I know that the current location is very convenient to many members. And I’m very committed to the idea of dealing with these waste materials in our own local community. It works, we just need to get a few things right.

No meat and cheese please!

The main thing that results in odours in the heap is when the wrong stuff goes in. Mostly members are putting the right stuff in the buckets (although I have seen some fish, cheese and even a whole piece of steak once, these are all no no’s). But sometimes even the right stuff can go a little wrong, when a bucket is left to sit too long. Any break down of materials in the collection buckets is not composting, it’s much more likely to result in fermentation or anaerobic decomposition. If veggie scraps in particular start to break down in the buckets they release a lot of water. That water can be handy in the compost heap (saves me having to water the heap) but in the bucket it sinks to the bottom and gets pretty gross if it doesn’t have access to air. Fear not though, I will accept a bucket in any state! If the occasional bucket gets forgotten about and left to rot then I can mix its contents into the heap and the ‘baddies’ producing the smells will quickly be vanquished by the change in conditions and hopefully also overwhelmed by the ‘goodies’ (the aerobic decomposers). But if too much stinky, slimy material comes into HCC then I might need to take additional measures.

Making microplastics, these were all collected on the tarp and sent to landfill though, unlike the good stuff that will now go in these barrels

I tried out a new tactic lately with the help of some barrels that I had been meaning to experiment with anyhow. These barrels were only going to be discarded before I rescued them so it was worth a shot putting them to work! I’ve actually had them in mind for a while, they may help extend the HCC network by acting as mini composting hubs. In the meantime, I transferred the stinky part of the compost to them and then also added fresh scraps to the barrels to give the main compost heap a bit of a break. This worked insofar as the compost in the wooden bays returned to the pleasant, earthy smell that it should be (as noted at the open day last weekend). But it did mean a lot of extra (and extra heavy) handling. And while the barrels were great in terms of containing any smells generated, they also amplified them due to not enough fresh air entering the barrels. So they are definitely not a long term solution, nor as good at composting as the wooden bays that Scott built.

luckily the pitchfork fits in, just

The barrels did generate a little heat though, when filled with a combination of half-composted materials, some dry leaves and some fresh scraps. So some composting was probably occurring. In which case, can they perhaps work as effective composting mini hubs, or at least appropriate holding bays for scraps?

Introducing the ‘host a barrel scheme’! The idea is to supply a barrel (with air holes for ‘breathing’) with a layer of dry leaves in the bottom, followed by a handful or so of half-composted materials to activate. Then the barrel can have scraps added to it gradually over the course of a month from a single, or a few households. This will work best if the scraps are layered with dry leaves (I should be able to supply these too, if needed) and the whole barrel can occasionally be rolled on the ground to give it all a good mix. One thing that could be a problem is if the barrels get overfilled, mostly because then I won’t be able to lift them!

I’ve since learnt that giving the barrels a gentle kick to roll them along is much more ergonomic than pushing!

Possible benefits of the scheme include getting the scraps into a compost-like environment before they have a chance to ferment on their own, as well as being easier for collections logistics, as I should only need to collect the barrel once a month. And this would also mean that they could operate in areas outside of the current collection area, maybe even Belconnen or Gungahlin! (South side would still be a bit of a trek, sorry).

So if you’d like to host a barrel send me a quick email and I can fill you in on the full details. In the meantime I’ll be maintaining the main heap and keeping it smelling sweet. I’ll keep an eagle eye out for any meat or fish (and leave it out for the currawongs) and if there is slime in the bottom of a bucket I might have to drain it and dry the contents before adding to the heap! Oh and I’m not going to put the larger buckets out front anymore, to encourage more frequent drop offs for those who drop straight to HCC headquarters (my place).

As usual, plenty to keep me busy. As long as I can keep composting then I’m happy with that 🙂

-Brook

HCC – for small buckets of scraps with nowhere else to go

HCCers meet Cass in Watson! Cass is a member of the HCC ‘targeted demographic’ as she lives in apartment with limited space for gardening or otherwise playing with soil etc.

Before I was in my late 30s and could finally afford to buy a house (with dual income, thanks Scott!) I lived in apartments/flats for years. Or rental houses, where I frankly wasn’t all that interested in setting up infrastructure such as a compost bin. So, I understand the desire to be responsible and sustainable with waste yet not really have the room or resources to do so. Cass was happy to join the HCC and know that her small volume of organic wastes were going to a better place than landfill.

That raises another pertinent point: Cass fills one of the small (2L) yogurt buckets each week. When I started the HCC some people didn’t think I would be interested in their scraps because they only generate a small amount. In fact the opposite is true! I’ve also had places like cafes and organisations offer to give me their kitchen waste ‘because they generate a lot’. I’ve been meaning to write a blog piece about how the aim of the HCC is not actually to produce compost… that’s merely a bonus. Suffice to say, the main aim is to avoid the generation of greenhouse gases from organic wastes and I think the best way to achieve that is to get as many people on board as possible in terms of being responsible with their waste. Some people are still not aware that sending our kitchen scraps to landfill is not the smartest move. But if each household can begin to consider alternatives then we can develop new systems around changed habits. Larger composting operations may be able to collect bulk food scraps from cafes and offices etc. and that is probably commercially viable to do so, especially as more organisations realise that that is a cost that they are willing to bear in exchange for other benefits. Collecting small bucketloads from households is a bit trickier. If enough people get on board, and follow my (very cheap!) suggested donations then it might become financially viable for the HCC. In the meantime I will continue to do what I can with the resources I have available 🙂

One other fantastic thing about Cass is that she is so committed to the composting cause that she is willing to talk about it with others. I didn’t actually realise that it was Cass’s word of mouth that led to another lovely member joining up (hello to Jen in Downer). Cass also remembered that although she uses the 2L buckets, I’m always a bit short for 3-5L buckets (perfect for larger households) so she made sure to nab an olive bucket from work and saved it from recycling. I’m always on the lookout for 3-5L post-consumer buckets (with lids) so thanks very much Cass!

So to anyone who is thinking of joining the HCC, especially if you live in an apartment or unit with limited outdoor space, and even if you don’t think you generate all that much in the way of scraps, you too could be cool like Cass!

A cosy autumn morning for the second HCC open day

Just last week I was joking with a workmate about how ‘it never rains in Hackett’ but I guess the joke was on me this morning as it rained this morning only during the HCC open day and not later in the day like the weather man said it should (although if we get some more after I write this that would be tops).

Regardless, it was a lovely cosy morning and the soft rain did not put me and other motivated compost lovers off. Everyone who came by got a good run down on the operations of the HCC, whether that was by way of my informal speech or private compost tours and demos. One of our newest members, Ingrid in Downer, even got stuck into a bit of pitchforking! and then long-time scraps donor Wen Wen followed her lead. Amazingly, Scott even did a little compost shifting 🙂 Ingrid and Maryann were impressed by the heat in the middle of bay 1 and thought the compost had a lovely, earthy aroma.

I told everyone about my plan to invest in an e-bike (probably a pedal-assist cargo trike…) to make the Saturday collections in Watson and Downer carbon neutral. An important announcement was the new ‘host a barrel’ scheme. I’ll write more about that in a follow-up blog post soon. New member Kaye signed up on the spot and gave me 3 months payment (‘suggested donation’) up front. Every little bit helps to get that bike, and hopefully a chipper somewhere along the line too. Apart from raising revenue I also suggested other ways that people can help the HCC. It’s prime time for leaf collection starting now, so thanks to Peter for dropping a bag off to get the donations started. Claire in Hackett thought she might be able to help with washing some buckets (I’ll rinse them first) and Katy in Gunderoo (she drops off scraps direct to Scott at their work), offered the services of her partner and his ride on mower! (to process leaves).

Overall there were lots of discussions about getting the word out about the HCC, how composting actually works, how to have more compost heaps to service other areas, particularly apartments, and what to do with the lovely compost when finished. Oh, and by all accounts lots of coffees and cups of tea were imbibed 🙂

Thanks to Katy, Scott and Ingrid for taking photos! Although the light rain showers might have scared off a few punters hopefully the pics show potential new members what a bunch of lovely people we are. Next time they can all come along and learn just how easy taking care of your kitchen scraps can be with the HCC.

Tying out the compost selfie station the day before

 

 

 

 

 

 

 

 

On the agenda

Me doing all the talking while Ingrid does all the hard work

Even spiderman got into some composting..

 

Keep on turning for best compost and lowest greenhouse gas emissions

Some people may be surprised by the quantity of kitchen scraps that the HCC heaps can process. The scraps from over 50 households are added to the heaps every week, along with a bunch of dry leaves to balance out the carbon and nitrogen. This amounts to a large volume of material, bay no. 1 can easily fill in a busy weekend. Yet as long as I keep the whole thing turning we will not reach capacity and there is still room for more scraps. That is because it only takes about a month for those fresh scraps to be ready to use as compost in local gardens. How are the HCC heaps so efficient? It’s about keeping the mix right but it’s also due to the hours I put in each week turning the heaps.

Once bay no. 1 is full it gets turned over into bay 2. Bay 2 can sit for a day or so and will reduce in volume a little as all of the critters, fungi and bacteria do their thing. But it won’t be long till I disturb their world once more by turning over bay 2 into bay 3. And once bay 3 is full? Do I move it all over into bay 4? Not yet! Nope, I get a bit more of a workout and actually start shifting bay 3 material back over into bay 1. Sometimes this feels like I must be a sucker for punishment, so it was great to find this recent paper backing up why I go to the extra effort.

 


In the paper, by Yang and others, they showed that mixing in mature compost is very beneficial when composting kitchen scraps. Not only are you providing inoculum of the good bacteria and fungi onto your veggie scraps and leaves/dry carbon materials, you’re also avoiding the generation of greenhouse gases. That’s great! as that is exactly the main motivation behind the HCC. All of the organic wastes that currently go to landfill release greenhouse gases when disposed of in that way. As opposed  to composting with plenty of available oxygen the scraps in landfill instead ferment and produce methane and nitrogen gases, very potent greenhouse gases. Compost heaps can also generate these gases, especially if they are not well managed. If a compost heap is producing unpleasant smells then it is releasing quite a lot of methane also (which has no smell). What the study by Yang and colleagues showed is that not only is turning of the compost needed, but also adding mature compost into the mix is very beneficial. They found that almost 70% of the greenhouse gases that would otherwise be released could be avoided by mixing in mature compost.

I already knew that the extra turning was a great thing to do but it’s lovely when some scientists have put in the work to quantify just how great an advantage it can be. One of the other benefits of shifting bay 3 material back to the start of the process is that I get to retain and manage moisture levels. Once a nice thick layer of fresh veggie scraps has been added to bay no. 1 (10-40L or so) I pile an equally thick layer of somewhat matured compost from bay no. 3. As the veggie scraps start to ‘cook’ in the middle of the heap condensate travels upwards and helps to re-wet the compost from bay 3 which was starting to dry out. It’s a rare occasion that any part of the compost heap needs to be watered.

I think there are also microbial ecology benefits of keeping the compost on the move. When it comes to the bacterial part of the community the interactions are certainly on the micro scale, with different sub-communities living on a fraction of banana peel as compared to another community living on the bread crust a centimeter away. ‘Challenging’ these communities by frequent mixing keeps the overall community diverse and active in many different ways. Let’s hope someone carries out some quantitative science on those fascinating aspects soon!

For now, I’ll get back to turning the compost 😉