What to Do if Your Compost Attracts Pests in an Urban Garden

Finding pests around your compost can be stressful, especially in an urban garden where space is limited and neighbours are close by.

If you’ve noticed rats, flies, or other unwanted visitors, it’s understandable to worry that composting might not be safe or suitable in the city.

The reality is this:

pests are not caused by composting itself, but by how food waste is managed.

With the right approach, composting can work safely and responsibly in urban spaces like Bristol.

Why compost attracts pests

Pests are attracted to easy food sources, not compost as a concept.

In urban composting systems, pest issues usually arise when food waste is:

• Left exposed

• Added in large quantities

• Not balanced with carbon material

• Put into systems that aren’t secure

Understanding why pests appear is the first step to preventing them.

Common compost pests in urban gardens

Rats and mice

Rodents are attracted to exposed food scraps and easy access points. They are more common when compost bins sit directly on bare soil without protection.

Flies

Flies are drawn to uncovered food waste, particularly fruit scraps. They are most active in warmer months.

Ants

Ants usually indicate compost is too dry rather than too wet.

How to prevent pests in compost

Always cover food waste

Every time you add food scraps, cover them with a layer of compost or carbon material such as:

• Woodchip

• Shredded cardboard

• Paper

• Finished compost

Covering food waste reduces smells and makes compost far less attractive to pests.

Use enough carbon material

Carbon-rich materials absorb moisture and create structure, which helps compost break down properly.

If pests are an issue, increase the amount of carbon material you’re adding.

Choose the right composting system

In urban gardens, system choice matters.

Well-suited options include:

• Enclosed compost bins

• Bokashi-style fermentation systems

• Community composting schemes

Open heaps are more challenging in small, shared, or densely populated areas.

Keep compost bins secure

Check that:

• Lids fit properly

• There are no gaps at the base

• Bins are in good condition

If possible, place bins on paving or add mesh underneath to prevent burrowing.

What not to add to urban compost systems

Unless your composting system is designed for it, avoid adding:

• Meat and fish

• Dairy products

• Oils and fats

• Large amounts of cooked food

These materials are more likely to attract pests and cause an imbalance.

However, there is a brilliant solution which allows you to safely compost meat, fish, dairy, and cooked foods. It's called bokashi fermentation. Bokashi excels through the power of microbes. Have you ever enjoyed fermented goods such as sauerkraut or kimchi? Well, the same microbe responsible for these processes can be applied to food scraps. In fact, it's so good we use it for the Generation Soil Bristol Living Compost Project.

If pests are already present

Seeing pests doesn’t mean composting has failed.

Steps to take:

1. Stop adding food waste temporarily

2. Add a generous layer of carbon material

3. Secure or relocate the compost bin

4. Review what’s been added recently

Often, making these changes is enough to resolve the problem.

Composting responsibly in Bristol

Urban composting works best when it’s:

• Well managed

• Thoughtfully designed

• Supported with the right knowledge

When done properly, composting reduces food waste in general bins, lowers smells overall, and supports healthier soil.

When to seek extra support

If pest problems persist despite making changes, the issue may be:

• System design

• Location

• Volume of food waste

• Lack of airflow or balance

At this point, general online advice can only go so far.

Get practical composting support in Bristol

If you’re struggling with pests around compost, Generation Soil’s Compost Clinic offer practical, hands-on support.

Compost Clinic can help:

• Identify why pests are appearing

• Adjust compost systems for urban conditions

• Build confidence with food waste composting

They’re especially useful in shared gardens, schools, and community spaces.

👉 Explore the Compost Clinic

👉 You can also explore our composting and soil workshops for deeper learning

Composting and pests: a manageable challenge

Pests don’t mean composting isn’t possible in the city.

They mean something needs adjusting.

With the right system, balance, and support, composting can be safe, effective, and neighbour-friendly, even in dense urban environments.