Remedying Pungent Compost Smells: A Step-by-Step Guide

In the world of composting, a smelly compost pile can be a common issue. Here are some simple steps to help you diagnose and fix the problem.

Identifying the Problem

The first step in troubleshooting a smelly compost pile is to identify the source of the odour. The scent of the pile can provide a clue for diagnosis. A rotten-eggs smell might indicate wet, anaerobic spots with trapped moisture, while a vinegar/sour smell usually means low oxygen and compaction. A musty/damp smell means the pile is overall too wet, and a smell like ammonia or fishy indicates too many fresh greens.

Quick Fixes

Quick fixes for common compost odour problems include adding browns (dry leaves, straw, or shredded paper), turning the pile to introduce air, and making air channels. If the pile is waterlogged, create drainage by adding coarse browns and tilting the container if necessary. For an acidic pile, add crushed eggshells or garden lime sparingly and mix in finished compost.

Regular Maintenance

To prevent future odors, maintain the compost regularly. This includes keeping it aerated, dry enough, and balanced with the right mix of greens (low carbon, like fresh kitchen scraps and grass clippings) and browns (high carbon, like dry leaves, straw, and paper). A rough C:N guide is 2-3 parts browns to 1 part greens by volume when the pile is very wet or heavy on food scraps.

Weekly Checklist

A weekly checklist can help catch small issues early. This includes turning or mixing the pile, adding dry browns if the pile is wet, burying any new food scraps, checking drainage, and adding biochar or finished compost if necessary. Covering fresh food scraps with a layer of browns (like leaves or shredded paper) can help cut flies and limit smell.

Long-Term Solutions

For long-term solutions, consider using biochar to lock up odor molecules and keep structure in the compost pile. Sawdust can be used to absorb moisture and add carbon to the compost pile, but it should be used sparingly to avoid slowing decomposition. Straw can be mixed in thin layers and is good for drainage.

Prevention is Key

Avoid adding large amounts of meat, dairy, or oily food to the compost, as they attract pests and strong odors. Packing scraps tight should be avoided, as leaving air pockets by mixing in coarse material like twiggy yard waste is recommended. Keeping tools near the bin (a pitchfork, a scoop of sawdust, and a jar of biochar) can help act quickly when a smell is spotted.

Conclusion

By following these simple steps, you can troubleshoot and fix a smelly compost pile, making composting a more pleasant and efficient process. Regular maintenance and careful management of your compost pile can help prevent odour problems in the future. Happy composting!