How to troubleshoot foul odors?
Written by
Julia Anderson
Reviewed by
Prof. Charles Hartman, Ph.D.The lasagna gardening method will occasionally emit smells that can only be described as similar to rotten eggs, and this sometimes occurs when the layers do not have sufficient oxygen. My first bed emitted awful odors after heavy rains saturated the greens. Anaerobic conditions emerge as the wet material compacts down. Act fast to return widespread airflow to the compost and mix carbon-rich browns with nitrogen-heavy greens.
Restore Airflow
- Turn layers with garden fork every 3 days
- Insert 1-inch PVC pipes with 10+ holes as vents
- Mix in shredded cardboard (2:1 ratio to greens)
- Reduce layer height below 6 inches
Neutralize Smells
- Sprinkle agricultural lime (1 cup per sq ft)
- Bury biochar chunks to absorb gases
- Add crushed mint leaves between layers
- Avoid meat/dairy in initial composting
Stop odors before they begin by balancing materials at the start. My clients in Seattle utilize buckets, often used for collecting kitchen scraps, to pre-mix their greens into chunky pieces with shredded paper, which is easy, as it doesn't matter what the consistency is. When layering, you want 3 inches of veggie peels and 6 inches of dry leaves. Squeeze a handful to see if moisture is present, if it drips, it is time to add more browns.
Material Prep
- Chop greens under 2 inches for faster breakdown
- Pre-compost weeds/grass in sealed bins for 1 week
- Line bottom with coarse branches for drainage
- Cover fresh layers with burlap (not plastic)
Moisture Control
- Place rain covers over beds during storms
- Use drip irrigation instead of overhead watering
- Check moisture weekly with $8 soil meter
- Add rice hulls to soggy zones
Ongoing odors mean underlying issues. My worst bed was completely rebuilt as rotting pumpkins had turned layers into compost slime. I fixed it as well as I could by adding 18 inches of straw over the top of the bed and returning to using proper ratios in my new bed. Check the bed weekly, and if everything goes correctly, the smell will be pleasant, and earthy, like forest dirt after it rains.
Read the full article: Lasagna Gardening Method: 10 Essential Steps for Success
