what can you not hot compost uk

2 min read 26-12-2024

Hot composting is a fantastic way to reduce your waste and create nutrient-rich soil for your garden. However, some materials are unsuitable and can even harm the composting process. This guide details what you can't hot compost in the UK, ensuring your compost heap thrives.

What is Hot Composting?

Hot composting, unlike cold composting, generates significant heat (often reaching 60°C or higher). This heat accelerates decomposition, breaking down organic matter much faster. This rapid breakdown requires the right balance of materials and careful management. Getting it wrong can lead to problems.

Materials to Avoid in Your Hot Compost

1. Diseased Plants & Invasive Species

Diseased plants, like those infected with blight or other fungal diseases, shouldn't be added. The heat might not kill all pathogens. These could spread to healthy plants when you use the compost. Similarly, avoid invasive species; their seeds could survive and spread in your garden.

2. Meat, Fish, Dairy & Oily Foods

These attract pests like rats and flies. The decomposition process also creates foul smells and can lead to anaerobic conditions (lack of oxygen), slowing down or stopping the composting process. They don't break down effectively within a hot compost system.

3. Fats, Oils & Greases

These materials are slow to decompose. They also repel beneficial microorganisms crucial for the hot composting process. They can create a slimy, unpleasant mess and impede proper decomposition.

4. Pet Waste

Pet waste contains harmful bacteria and parasites that pose risks to human health. Composting it improperly is unsafe. Dog waste, in particular, carries disease risks. Avoid adding this to any compost, including hot compost.

5. Cooked Foods & Bread

While scraps of uncooked vegetables are fine, cooked foods and bread can attract pests. These items also don't decompose as readily as raw materials. They often become slimy and foul-smelling, hindering proper decomposition.

6. Treated Wood & Plastics

Treated wood contains chemicals that are harmful to the environment and the compost itself. Plastics are non-biodegradable and contaminate your compost. Never add these materials to your compost.

7. Weeds with Seeds

While some weed materials are okay, adding weeds with viable seeds can lead to the spread of unwanted plants in your garden. Ensure weeds are thoroughly dried out or composted for a long enough time to kill the seeds before using the compost.

8. Coal Ash & Chemical-Treated Materials

These materials contain harmful substances that contaminate your compost and harm plant life. Never add chemicals, pesticides, or similar substances to your compost.

What to Do With These Materials?

Food waste: Check your local council's guidelines on food waste recycling. Many areas have dedicated food waste collection services.
Diseased plants: Dispose of these in your regular trash or burn them if permitted in your area.
Pet waste: Dispose of this in a sealed bag in your regular trash.
Treated wood and plastics: Dispose of these according to your local council's guidelines.

Maintaining Your Hot Compost Heap

Even with the right materials, maintaining a hot compost requires attention:

Sufficient moisture: Keep your compost damp like a wrung-out sponge.
Regular turning: Turning your compost introduces oxygen, crucial for the decomposition process.
Appropriate carbon-to-nitrogen ratio: A balanced ratio is essential for successful hot composting.

By avoiding these materials and following proper composting techniques, you can create healthy, nutrient-rich compost for your garden. Remember to always check your local council guidelines for disposal of unsuitable materials.