How to run the sock experiment
The whole test takes about fifteen minutes of work, spread over two months. Follow these steps and your results will be comparable with every other site in California.
- 1Gather your materials
One clean, unused 100% cotton sock (check the label — any polyester or nylon will not break down). A trowel or spade, a marker flag or stake, and a phone camera.
- 2Photograph the sock before burial
Lay the sock flat in good daylight on a plain surface and take one clear photo. This is your 'before' image — it's what makes your result comparable to everyone else's.
- 3Bury it 6–8 inches deep
Dig a narrow trench, lay the sock flat and horizontal (not bunched up), then backfill and press the soil down firmly so there are no air pockets. Water the spot lightly if the soil is dry.
- 4Mark the spot and wait ~60 days
Flag or stake the location and note the date. Sixty days is the standard window — shorter experiments are still welcome, but they aren't directly comparable to full-length ones.
- 5Dig it up carefully
Excavate around the sock rather than pulling on it, since decomposed cotton tears easily. Gently shake or rinse off loose soil — don't scrub, or you'll destroy the evidence.
- 6Photograph the 'after' sock
Same setup as before: flat, plain background, good daylight. Try to match the angle of your first photo so the two images line up visually.
- 7Submit your results
Upload both photos, set your burial and recovery dates, estimate how much of the sock decomposed, choose your location visibility, and add any observations.
- Using a blended sock — anything but 100% cotton won't decompose properly.
- Burying it too shallow or too deep; 6–8 inches is where most biology lives.
- Bunching the sock into a ball, which limits soil contact.
- Forgetting the 'before' photo, or shooting it in poor light.
- Scrubbing the recovered sock, which removes the decomposition you're measuring.
- Losing the spot — always flag or stake it.
Reading your results
Little biological breakdown. Often compacted, very dry, or low in organic matter.
A working soil food web. Typical for many gardens and managed landscapes.
Very biologically active soil, usually rich in organic matter and moisture.
Results vary with climate, season, and moisture, so a lower number isn't a failure — it's data. Every submission makes the statewide picture sharper.
Finished your 60 days?
Add your photos and put your site on the map.