Composting is a fantastic way to recycle food and garden waste, but not all materials are compost-friendly. Knowing what can and can’t go into your compost pile helps keep it balanced, pest-free, and nutrient-rich. Here’s a quick guide to compostable and non-compostable items to help you get the most out of your compost.
Compostable Materials: What CAN Be Composte
1. Greens (Nitrogen-Rich)
These materials are high in nitrogen and help keep your compost “cooking” by providing essential nutrients and moisture.
- Fruit and Vegetable Scraps: Peels, cores, and trimmings from fresh produce.
- Coffee Grounds and Filters: Adds nitrogen and a rich texture.
- Tea Bags: Compostable if they’re made from natural fibres (check if they’re plastic-free).
- Eggshells: Rinse and crush for faster breakdown; they add calcium.
- Grass Clippings: Use in moderation as they can compact and get slimy.
- Garden Waste: Deadheaded flowers, soft stems, and green plant trimmings.
2. Browns (Carbon-Rich)
Browns provide structure, aeration, and help balance the moisture level in your compost.
- Dry Leaves: One of the best brown materials, especially in autumn.
- Cardboard and Paper: Shredded paper, egg cartons, and cardboard (avoid glossy or coloured prints).
- Wood Chips and Sawdust: Use untreated wood only and add in small amounts.
- Straw and Hay: Great for aeration and adding bulk.
- Corn Cobs and Stalks: Break them up as much as possible for faster decomposition.
- Pine Needles: Use sparingly as they’re acidic, which can balance alkaline compost.
3. Other Organic Materials
These can add extra nutrients and enrich your compost.
Natural Fabrics: Small scraps of untreated cotton, linen, or wool (avoid dyed or synthetic fibres).Non-Compostable Materials: What CAN’T Be Composted
Herbivore Manure: Manure from animals like chickens, rabbits, and cows adds nutrients but let it compost fully before using.
Nut Shells: Only compostable shells like walnut and almond (avoid black walnut shells).
Hair and Pet Fur: Adds nitrogen but break it up to prevent matting.
Natural Fabrics: Small scraps of untreated cotton, linen, or wool (avoid dyed or synthetic fibres).
Non-Compostable Materials: What CAN’T Be Composted
1. Animal Products
Animal products can attract pests, cause odours, and don’t break down as well as plant-based materials.
- Meat and Bones: These can attract rodents and pests and take a long time to break down.
- Dairy Products: Cheese, milk, and butter create odours and can cause a slimy compost pile.
- Grease, Oils, and Fat: Can slow down decomposition and attract unwanted pests.
- Fish and Seafood: Like meat, it can attract pests and emit strong odours.
2. Processed or Treated Foods
Processed foods contain preservatives, fats, and oils that can disrupt the composting process.
- Bread and Baked Goods: Although technically compostable, they attract pests. Use sparingly if at all.
- Pasta and Cooked Grains: These can attract pests and break down poorly.
- Sugary Snacks: Candies, biscuits, and cakes add sugar, which attracts pests and disrupts microbes.
3. Non-Biodegradable Items
Anything synthetic or coated with chemicals doesn’t break down in a compost pile.
- Plastic and Foil: Even small scraps of plastic can contaminate compost.
- Synthetic Fabrics: Polyester, nylon, and acrylic don’t biodegrade.
- Tea Bags with Plastic: Some tea bags contain plastic, which won’t break down. Opt for plastic-free tea bags.
4. Treated Wood and Sawdust
Chemically treated wood can introduce toxins into your compost.
- Pressure-Treated Wood: Contains chemicals harmful to plants.
- Painted or Stained Wood: Coatings can release toxins into your compost.
5. Pet Waste from Carnivores
Waste from meat-eating animals can introduce pathogens and isn’t suitable for typical composting.
- Dog and Cat Waste: Contains bacteria and pathogens. Only compost pet waste in specialised pet waste composters.
- Cat Litter: Most conventional litters are not biodegradable, and even natural ones are risky due to waste contaminants.
Special Notes and Tips
- Citrus Peels: Citrus is technically compostable but can be too acidic for some composts. Use sparingly.
- Onions and Garlic: Also compostable but can deter worms, so balance carefully in a worm bin.
- Weeds and Invasive Plants: Avoid composting aggressive weeds like bindweed or plants with seeds unless your compost gets very hot and can kill seeds.
- Diseased Plants: Avoid adding diseased or insect-infested plants to prevent spreading issues to your garden.
Following these guidelines helps keep your compost pile balanced, efficient, and free of contaminants, giving you rich, high-quality compost to nourish your garden! Happy composting! 🌍🌱