Compost Trial: Underwear Challenge

I put Tend's soil-to-soil undies to the test!

To conclude our series on the intersection of fiber and soil, here is a (mostly) visual story of how Tend undies became food for microbes in my compost bin!

The Compost Pile

I built this compost at the community garden in my neighborhood! I aimed to make the initial volume about 75% carbon and 25% nitrogen. From then on, any time I added nitrogen inputs (mostly food scraps), I’d add an equal amount of carbon. This is how I’ve learned to keep at-home composting super simple and balanced long-term!

It’s also good to aim for a 3-cubic foot heap to maintain good thermal mass, but not so big that it’s heavy and compacts. In reality, this pile is about 3 - 4 feet wide and deep, and 2 - 3 feet tall at all times.

The pile had been active for a few weeks, readily decomposing food scraps and maintaining good moisture and temperatures ~120 - 130F (my preferred sweet spot for backyard composting).

Feedstocks / Inputs

• Carbon | two-thirds: wood chips, aged mushroom substrate, aged weeds, shredded newspaper

• Nitrogen | one-third: fresh weeds, grass clippings, food scraps, coffee chaff, coffee grounds

Volumes were measured using my #1 tool: buckets!

The Trial

Tend garments are made of all-natural, compostable materials and we set out to see if they’d readily breakdown in a reasonable time frame in a typical at-home composting setting.

Brightly colored zip ties were added to the garments and a small medley of material scraps so I could find them easily in the pile. One pair had been naturally dyed with indigo, the other had no dye. I checked on them every 5 days to take progress photos on a white poster board background. During the trial, I treated the pile like normal - adding food scraps about once a week, managing moisture and turning as needed (maybe once during the 30-day trial after a big storm).

On Day 1 I dug a few small holes into the belly of the compost and added the samples. I gave the pile a good soak with the hose and eagerly awaited the first check-in.

If I were to do this again, I’d dunk or soak the clothing in water before adding to the pile. Also, we kept the garments whole to make clearer observations (plus, it’s just more fun that way!), but they’d presumably decompose even faster if they were cut up into smaller pieces.

By Day 5, the first time I unearthed the undies, there was already mycelium (fungi) visibly growing on one of the garments. It was even growing on the elastic band just days into the decomposition process - very exciting!

On Day 10 the garments had some holes in them and more mycelium was found on some elastic included in the materials medley.

Remember, as Tend founder Katie Troutman explained in our interview, most elastic contains elastane - a petroleum by-product - and is not environmentally safe for composting. This elastic was derived from rubber trees.

Day 15 proved even more hole-y (that’s the technical term 😉) and sheer.

Day 20 was a dramatic leap for the blue pair which were quickly decomposed from a brief to a thong shape - I told you soil was sexy!

Day 25 the white pair caught up and mostly had the perimeter / hemmed parts in tact, but the threading was loose. The elastic in the medley and the garments were becoming noticeably thinner.

By Day 30, there was very little cotton left and only a bit more work to be done on the elastic. All signs were pointing to that material being steadily decomposed. After another couple weeks or so, I couldn’t make out any perceptible parts of the garments as I visited the pile.

The Microbial Assessment

Lastly, we assessed a sample of the compost under the microscope! I collected the sample by scraping off bits of compost clinging to the remaining materials. We found a suite of beneficial microbes living in these aggregates. I even found what I believe to be microscopic strands of the elastic - there were microaggregates clinging to it like little microbial neighborhoods settling on a substrate rich in resources. 👇

Microaggregates on microscopic, naturally-derived elastic | 400x

Bacterial Feeding Nematode | 400x

Fungi | 400x

Purple Testate Amoeba | 400x

Naked Amoeba | 400x

So there you have it. All the natural components that made up the garments came from soil and once again were returned, happy microbes ‘n all. ✨

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The Lesson

I cannot adequately explain how much this experience of working with Katie and Tend has impacted me. It’s truly tuned my compass! 🌟

In a busy modern life it can feel impossible to set and maintain high standards. We can’t practically make thoughtful decisions that align with our values for every single purchase / consumable. But, that’s not the goal. The call to action is to delight in something that resonates with your values, even if it’s small in the grand scheme of your life, because that’s where big changes often start.

With love,

Andie