Composting issues and how to fix them for a successful compost bin

Composting is a brilliant way to turn food waste into nutrient-rich soil, but it’s not always as simple as tossing scraps into a pile. Many people struggle with the composting process due to mistakes that lead to bad odours and slow decomposition. If you’ve ever had a smelly, soggy, or dry and fibrous compost pile, you’re not alone! The good news is that these problems are easily fixed with the right adjustments and techniques.

In this guide, we’ll cover the most common compost problems and how to fix them to ensure a thriving, living compost bin full of a world of microorganisms and worms.

1. Not balancing green and brown compost materials in your compost bin

A healthy compost bin relies on a proper balance of nitrogen-rich (green) and carbon-rich (brown) materials. Too much organic material from one category can slow decomposition and cause problems.

The fix: it's all about balance!

• Greens (nitrogen-rich compost materials): Grass clippings, food waste, fruit scraps, coffee grounds.
• Browns (carbon-rich compost materials): Dry leaves, shredded paper, cardboard, straw.
• Aim for a ratio of about 2 to 3 parts brown for every 1 part green.

Maintaining this balance is key to avoiding excess moisture, foul odours, and slow decomposition. If your pile seems sluggish, reassess the mix and adjust accordingly. A simple way to monitor is by observing the texture—if it's too wet and slimy, add more browns; if it's too dry and fibrous, add more greens.

2. Compost pile is too wet or too dry: managing moisture issues

Moisture is essential for the composting process, but too much or too little can hinder progress. A wet compost heap becomes anaerobic, leading to bad odours, while a dry pile decomposes too slowly.

The fix:

• If the moisture level is too high, add dry materials like shredded leaves, cardboard, or paper to absorb excess moisture. Ensure there are no adhesives, sticky tape, or plastic coatings on these materials.
• If the moisture content is too low, sprinkle it with water until it feels like a wrung-out sponge. For a large, dry pile, turn it into a new bay while adding water for the best results.

3. Lack of aeration in your compost pile

Microorganisms responsible for decomposing materials need oxygen to thrive. Without enough aeration, your compost can become compacted, smelly, and slow to break down.

The fix:

• Turn the pile or your compost bin regularly to introduce oxygen and create an aerobic environment.
• Use a product like Food2Soil's Compost Booster to accelerate the process.
• Shred compost materials like cardboard or branches before adding them to prevent compaction.

4. What should and shouldn’t go into your compost bin

This is where most guides will tell you not to add dairy, meat, oils, citrus, or onion skins. However, if it was once living, it can go in your compost heap—as long as you maintain the right balance. When managed correctly, all organic material will break down effectively.

Managing pests and odours:

• To avoid attracting pests, use an enclosed system like a tumbler compost bin.
• Bury food scraps deep within the pile and balance with plenty of carbon-rich compost materials.
• Use a worm bin for safe, odour-free worm composting.

What to avoid:

While most organic materials can decompose, some should be kept out of your compost bin because they introduce toxins or don’t break down properly:

• Chemically treated wood or paper
• Diseased plants or invasive weeds
• Plastic or synthetic materials

5. Compost pile smells bad: a common composting mistake

A properly balanced compost pile should smell earthy, not rotten. Bad odours often indicate too much moisture, anaerobic conditions, or too many nitrogen-rich compost materials.

The fix:

• Mix in dry compost materials like shredded paper or straw to balance excess moisture.

• Turn the pile regularly to increase aeration. Compost aerator tools are a great help!

• Avoid adding too much nitrogen (grass clippings, food scraps) without enough carbon.

If it's really bad, adding crushed eggshells or lime (please, not builders lime!) can help neutralise acidity levels, which can contribute to foul odours.

6. Compost heap isn’t heating up: perfect compost needs heat

A good compost pile is full of microbes breaking down organic material. When working well, thermophiles (heat-loving microbes) do the work. If your compost heap stays cold, it lacks the right conditions for these microbes to thrive.

The fix:

• Add nitrogen-rich compost materials like coffee grounds or grass clippings.
• Turn the pile more often to boost oxygen levels.
• Make sure your compost bin is large enough (at least 3x3 feet) to retain heat.
• Ensure that it is moist.

7. Compost is taking too long to decompose: managing particle size

If your compost is breaking down too slowly, it could be due to large materials, lack of moisture content, or poor balance between greens and browns.

The fix:

• Shred compost materials like cardboard, leaves, and food waste before adding them to reduce particle size.
• Ensure you have enough microorganisms by using finished compost as an activator or adding Food2Soil's Compost Booster.
• Keep a consistent turning schedule to maintain airflow.

8. Not understanding when your compost is finished

Many people let compost sit too long, delaying the benefits of enriching their soil. Finished compost should be dark, crumbly, and have an earthy smell. If there are some larger pieces that haven't broken down yet, simply put them in the next batch of compost—they will provide a microbial boost to kickstart the process.

The fix:

• Feel the compost—if most of it is crumbly and dark, it’s ready.
• Smell it—a pleasant, earthy scent means it’s good to go.
• If there are a heap of worms present, the pile has cooled down from its 'hot' phase, and the worms are finishing the job. If you have worms, you've succeeded!

Conclusion: turning composting mistakes into success

Composting isn’t just about reducing waste—it’s about creating a thriving, balanced ecosystem that supports soil health, plant growth, and sustainability. By making simple adjustments, you can transform food scraps and organic materials into nutrient-rich compost that enhances your garden, reduces landfill waste, and contributes to a healthier planet.

Keep experimenting, stay patient, and soon, you’ll have the perfect compost bin teeming with beneficial microorganisms and worms. With the right balance of greens, browns, moisture, and aeration, you’ll turn composting mistakes into a sustainable success.

Happy composting!