Dry corrugated cardboard and shredded paper is easy for composting bacteria to digest (see table below).
Because they are also very ‘dry’, i.e. have very low water content (typically less than 5% water), they are the best materials to add to wet food waste to balance things out and ensure there is enough heat to drive off excess water as steam.
By the way this use has nothing to do with aeration and very little to do with balancing carbon/nitrogen ratios!
(Please note – Ignore the advice on many cold composting sites that scrunched up newspaper and or cereal packet cardboard will provide aeration – in the HOTBIN they WILL NOT create aeration pockets – quite the reverse – the paper and card will be soaking wet within hours and form a matted impervious layer to airflow. It is highly likely the newspaper will come out when you empty the bin as a flattened blob of soggy newspaper.
It is essential you mix both the paper and the cardboard into the waste rather than just add it in as a layer on the top. When adding food waste ALWAYS also add bulking agent. The bulking agent will form a supportive structure (think building blocks) around which air can flow.
Why will paper and corrugated paper compost quickly but not newspaper?
It is easy to think all paper products come from wood so they should all decompose at the same rate.
We know that thin high surface area materials will decompose faster – so cardboard is faster than a wood branch piece as the bacteria have more surface area to attack. If we assume and example where surface area is the same and the temperature is the same, the speed at which wood products compost is directly related to the amount of lignin contained – so hard wood decompose slower than soft woods.
We can take this analogy a little further to explain newspaper and white office paper – the comparison is made in the table below.
|White paper (e.g. office, A4 copier, coffee filters)
||The caustic part of the Kraft paper pulping process removes lignin to leave only cellulose fibres.Shredded it rather than crunch it up. Sprinkle in little and often – thick layers will quickly get wet and form an impervious mush that prevents airflow.
|Corrugated brown cardboard boxes, egg cartons
||Although processed, about 5-10% lignin remains.Corrugated cardboard has the advantage of trapped air/air channels. Shredded or tear up – large sheet will block airflow
|This is low cost paper – the expensive lignin removal stage is not undertaken – it is small wood fibres. (Compare to white office paper above).Ensure shredded or scrunched up. It will compost far more slowly than food, grass and most other wastesDo not add whole cereal boxes – tear up and spread / mix into waste. Add sparingly – if attempting to dry wet waste, much better to use office paper or corrugated cardboard.
|Wax coatings are slow to decay. Higher temperature allows addition in HOTBIN
How do I create lots of chopped up cardboard quickly?
Everyone tends to have corrugated cardboard boxes, but tearing them up can be tiresome. You can quickly cut into strips using a craft or Stanley knife – but you need to take care and do this correctly to avoid taking your fingers of! A safer way is to see if your office shredder is a ‘multi sheet’ unit. If it is it will shred 8 sheets of paper at a time and you will find it will shred most cardboard boxes. See photo’s below. Please keep in mind if you put too much strain on a low sheet feeder it will just overheat and conk out!
A useful post on dealing with excess water in the HOTBIN can be found on our online FAQ : Excess Water Post
Yes you can compost it. BUT!!
Problems will arise if the heap does not get above 40C – the seeds will survive cold composting and you will spread the seeds when the compost is used. A hot compost heap (40-60C) will kill the seeds.
However as this is such an invasive and tough weed, you need to check that the seeds/bits are only added to the top of a already hot pile, that they stay near the top (do not fork in or turn the pile/HOTBIN as seeds will fall down to cooler base). Finally, after hot composting, give your compost a ‘germination test’ – By this we mean leave the compost in an open maturation pile for a few months to check to ensure the Horsetail does not re-sprout. If it does, gently tease out all roots and rhizomes again and zap it through the hot compost again.
This may sound painstaking – but so will your efforts to remove it from soil in the first place. Are there any other options? Passing the waste on to your local authority to handle is not a great option. The seeds and bits can drop and disperse on roads and neighbours plots. If you are unsure, perhaps this is one case where it is better to burn the weeds (subject to local authority rules of course!).
- Horsetail or Mare’s Tail (Equisetum Arvense) is an invasive, deep-rooted perennial weed with fast-growing rhizomes (underground stems) that quickly send up dense stands of foliage that will spread quickly to form a dense carpet of foliage, crowding out less vigorous plants in beds and borders.
- Horsetail is easily recognised by its upright, fir tree-like shoots that appear in summer. In spring, fertile light brown stems, 20-50cm (10-20in) tall, appear with a cone-like spore producing structure at the end of the stems. In summer, sterile green shoots develop into fir tree-like plants, 60cm (2ft) tall.
- The creeping rhizomes of this pernicious plant may go down as deep as 2m (7ft) below the surface, making them hard to remove by digging out, especially if they invade a border. They often enter gardens by spreading underground from neighbouring properties or land.
You can also find more advice at: Garden Organic Website
A question we often get asked is; do I need to keep my Wormery now I have a HOTBIN?
The simple answer is no and the key benefit is that the HOTBIN can compost both food waste and garden waste. Therefore you can save space, reduce costs and still keep your food waste out of landfill.
So what is worm composting?
Worm composting is using worms to recycle food scraps and other organic material into a valuable soil amendment called vermicompost, or worm compost. Worms eat food scraps, which become compost as they pass through the worm’s body.
So what is HOTBIN composting?
The HotBin is a simple design that helps maximise what nature does by bringing together the right conditions to make hot composting easier. It does this by providing effective aeration between the bottom air inlet plate and the air outlet rotating valve, removing excess water through the valve as steam and allowing you to control the rate of heat loss. You can compost 100% of all domestic food waste in the HOTBIN without inherent problems with odour, vermin and flies. This includes left over meals, plate scrapings, meat, fish, small bones, bread, cakes, pasta and rice. Your food and garden waste will be turned into rich organic matter for the garden every 90 days.
Worms in the HOTBIN?
You do not need to add worms into the HotBin however you can – either directly by adding into the base layer (which is cooler) or inadvertently by adding worm eggs and worms into the bin via small bits of soil and old compost . Most of the worms and worm eggs will be killed by high temperatures (>45C) but a some will find there way down into the base layer and continue to work on the base layer compsot.
However, worms can be beneficial to composting and can be added if you want to. But a word of warning do not add them into the upper active layer (60°C will kill them) only add worms via the hatch panel where the compost will be cooler. Worms will help to decompose waste and leave mucus in the compost which is proving beneficial to soil fertility.
As the HOTBIN is no ordinary composting bin as you can use it to recycle than just vegetable kitchen waste in it. The hot temperatures achieved during hot composting make composting all food waste in the HOTBIN a safe home composting system that recycles a whole lot more than just potato peelings.
So if you were thinking about a Wormery as a form of recycling food waste why not consider a HOTBIN as it composts both your food and garden waste together.