Composting 101: what to put in your compost bin (and what to avoid)
In a previous article on our blog, we’ve covered why composting is important if you want to live a more sustainable lifestyle. That’s why we thought that now would be the perfect time to give you some more practical tips on composting and share which things to compost and which should be avoided.
Once you’ve got your compost bin, vermicomposter or compost pile set up at home, you can regularly refer to this guide to check about any items you’re unsure of. In a few weeks or months, composting will likely become second nature and you will no longer need to look up what can and cannot go in your compost bin.
Straight into your compost bin
These are items that can go directly into your compost bin, without a second thought. No prep time is necessary. Just remember - you always need a good mix of green (nitrogen) and brown (carbon) materials.
- Fruit and vegetable scraps – from potato peels to a mouldy strawberry that has been sitting in the back of your fridge for a little too long
- Old or dry herbs and spices that you cannot use anymore
- Coffee grounds, loose leaf tea or tea bags (unless they’re made from or glued together with plastic)
- Old beer or wine – add gradually if you have a small compost pile
- Pet bedding and droppings from herbivores such as rabbits, guinea pigs or hamsters
- Stale dry pet food
- Grass trimmings and leaves
- Tissues and paper towels, unless they are soaked with grease or other things which don’t belong in the compost bin
- Cotton wool, unless soaked with makeup
- Sawdust and wood chips
- Hair – human or pet
- Dryer lint and dust from your vacuum
- Toothpicks made from wood
- Spoiled plant-based milk alternatives, such as oat milk, almond milk or soy milk
- Uncooked rice or pasta
- Unpopped popcorn kernels
- Tofu, tempeh and other plant-based meat alternatives
- Paper muffin or cupcake cups
- Cotton swabs, if they’re made with cardboard/bamboo sticks and not plastic
- 100% cotton tampons and cardboard applicators (new or used)
- Nail clippings
- Pencil shavings
- Dust clusters
- Crumbs from your table or kitchen countertop
- Wilted flowers or dead houseplants, unless they’re diseased or insect-ridden
- Soil (from old, dead plants or leftovers from repotting)
- Natural potpourri
- Used matches
- Hay and straw
Items that require some preparation
Aside from the items which can go directly in your compost bin, there are some which require a little more preparation. This usually means they need to be shredded, cut up or ground up into smaller pieces so that they can compost quicker, without staying in your compost for too long.
- The cardboard and cornstarch packaging from our sponges - just tear it up first.
- Our compostable sponges - just cut them up first.
- Eggshells – crush them to decrease the time they take to compost
- Non-glossy newspapers, leaflets, magazines, and receipts – shred into small pieces
- Paper bags – shred or cut up
- Natural fabrics such as cotton, linen, or hemp (ensure there are no polyester tags or print) – cut up into small pieces
- Cardboard, egg cartons and toilet rolls – shred or cut up
- Coffee filters – shred or cut up
- Pine needles and pinecones – break them up into small pieces
- Nutshells (except walnut) – grind them up
- Twigs and branches – need to be broken up into small pieces
- Dry pasta – break up into smaller pieces or cook
- Seeds (pumpkin, sunflower…) – chop them up, as they could sprout if they’re not roasted
- Wine corks or other cork items – chopped up
- Old natural loofah – cut up
- Corn cobs – need to be broken up into smaller pieces
- Avocado seeds (and other large seeds) – need to be broken up into smaller pieces
- Burlap sacks – shredded or cut up
- Ashes from wood – only in very small amounts
- Plastic-free wrapping paper – shredded or cut up
- Pumpkins – smashed up or broken into pieces
- Christmas trees – broken up or chipped in a woodchipper
- Seaweed – rinse off any saltwater
Items that can’t be composted – and why
Lastly, there are some items that are just a no-go for composting. This can be for a few different reasons; we’ll share these alongside each item.
- Meat or fish scraps, including fat or grease (attracts pests and creates odour problems)
- Eggs – except shells and dairy products (attracts pests and creates odour problems)
- Coal or charcoal ash (the resulting compost would contain substances harmful to plants)
- Plants or yard trimmings treated with pesticides (may kill composting organisms)
- Droppings from carnivorous pets (can contain parasites or germs)
- Walnut tree leaves and twigs, as well as walnut shells (the resulting compost would contain substances harmful to plants)
- Diseased plants (disease may spread)
- Oil (attracts pests)
- Cooked food is not recommended, if pests have easy access to the composter.
If you can still use it, don’t compost it!
While many different items can be composted, think about whether you could still use an item rather than composting it right away. Old clothing you no longer wear could make someone else happy, cardboard or cork could make a great basis for DIY projects and many other items can be upcycled for new use.
Many fruit and veg scraps which we would normally throw away can still be used in a variety of ways. Unless mouldy, old fruit can be used for jam and preserves or frozen for smoothies. Blackened bananas make the best banana bread. Don’t peel your veggies such as potatoes, cucumbers or carrots unless you need to – the peels are perfectly edible. Scraps from onions, carrots or parsnips can be boiled to make homemade veggie stock before composting. There are many creative ways to use these items and throwing them to the compost pile straight away would be a waste.
Think out of the box, find uses for your scraps, limit your food waste and compost whatever is leftover.