All wood based materials like leaves, twigs, paper and card can be composted.
We know that small pieces of wood with high surface areas will decompose faster than lumps – sawdust decomposes faster than shavings which compost faster than the original wood branch. If we assume the 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 in the wood.
A hard wood decomposes slower than soft wood. It is easy to think ‘paper comes from wood, so all paper products will decompose at the same rate’- but this is not the case. Newspaper and white A4 office paper decompose at very different speeds.
To explain why, let’s review the Kraft paper pulping process in the table below:
If using a mobile device turn your screen landscape to help readability.
|
Speed (At 60°c) |
Paper / Card Type |
Notes |
|
Fast (days) |
White Paper |
The caustic part of the Kraft paper pulping process removes lignin to leave only cellulose fibres. Cellulose is easy for bacteria to digest when compared to lignin. Shred it rather than crunch it up. Do not pre-soak, this must be dry. Sprinkle in little and often - thick layers will quickly get wet and form an impervious mush that prevents airflow. |
|
Fast (days) |
Corrugated Brown Cardboard (boxes, egg cartons) |
Corrugated cardboard is highly processed and only 5-10% lignin remains. Corrugated cardboard has the advantage of trapped air/air channels. Shred or tear up - large sheets will block airflow - please do not pre-soak, this must be added dry. |
|
Medium (weeks) |
Newsprint / Papers, Sheets of Card |
This is low cost paper – the expensive lignin removal stage is not undertaken. The paper is made from small wood fibres not cellulose fibres per office paper and corrugated card. These are best recycled in your paper collection waste. If you do use, ensure sheets are torn or scrunched up. It will compost far more slowly than food, grass and most other wastes, so do expect it to be present in final compost – normally as blobs of very compressed paper. |
|
Medium (weeks) |
Gloss Printed, Waxy Papers |
Wax coatings are slower to decay. Higher temperature allows addition in HOTBIN, but again add sparingly. Better collected and recycled. |
|
Medium (weeks) |
Autumn Leaves |
The stems of leaves are woody. For fast results, ensure leaves are shredded. Mix large amounts (>10 litres) into easy to compost food waste to avoid them forming a matted thick layer which will prevent airflow. Large volumes will also need extra nitrogen - so have chicken poo or blood bone meal on hand. |
|
Slow |
Woody Twigs / Soft Woods / Hard Woods |
All wood (lignin) is harder and slower to compost. When trying to compost wood - shred and chop as small as possible - surface area will determine the speed of decomposition. For example, sawdust composts faster than shavings which are easier to compost than woodchips and branches. We do not advise adding sawdust or shavings into the HOTBIN as it can block airflow. |
What Types of Waste Can I Compost?
|
|
Will it Decay |
Cold |
HOTBIN Compost |
HOTBIN Rate of Decay |
Comments |
|
Cardboard (cereal box, paper plate) |
Yes |
Not Advised |
Yes |
Medium |
High in lignin so be careful to shred before adding to the HOTBIN and not to add a lot in one go. |
|
Card (inside of toilet rolls, kitchen rolls) |
Yes |
Yes |
Yes |
Medium |
High in lignin so be careful to shred before adding to the HOTBIN and not to add a lot in one go. |
|
Corrugated Cardboard Boxes |
Yes |
Yes |
Yes |
Fast |
Shred before adding to the HOTBIN. |
|
Egg Cartons |
Yes |
Yes |
Yes |
Fast |
High in lignin so be careful to shred before adding to the HOTBIN and not to add a lot in one go. |
|
Glossy Magazine Paper |
Yes |
Not Advised |
Yes |
Medium |
This can take a long time in cold composting bins. Shred when adding to the HOTBIN. |
|
Laminated Paper |
Yes/No |
No |
No |
Medium |
Most laminates are plastic or aluminium foil and are therefore not compostable. |
|
Newspaper |
Yes |
Yes |
Yes |
Slow |
High in lignin so be careful to shred before adding to the HOTBIN and not to add a lot in one go. |
|
Printed Paper |
Yes |
Not Advised |
Yes |
Medium |
Can take a long time in cold compost bins - shred before adding to the HOTBIN. |
|
Sawdust |
Yes |
Yes |
Not Advised |
Medium |
Due to the small particle size this can block the airflow possibly creating an anaerobic bin. |
|
Shavings |
Yes |
Yes |
Yes |
Slow |
Can take a long time in cold compost bins - if too much is added, airflow can become blocked. |
|
White Office A4 Paper |
Yes |
Yes |
Yes |
Fast |
Shredded A4 office paper is surprisingly easy to compost. |
|
Wood Based Waste |
Yes |
Yes |
Yes |
Very Slow |
|
|
Wood Treated with Preservatives |
Yes |
Yes |
Yes |
Very Slow |
Take care - read the back of the preservative tin/bottle. Most modern day preservatives are biodegradable and therefore compostable. |
|
Woody Twigs / Branches |
Yes |
Yes |
Yes |
Very Slow |
Chop or shred to less than 4cm where possible. |