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SHIRT to DIRT citizen-science experiment FAQ

Updated: Jun 17, 2023

shirt to dirt experiment faq

Your questions about Shirt-to-Dirt, answered!

The Shirt-to-Dirt Experiment is taking place from June-August 2023. Learn more about it and sign up here! These are all of the questions we got from the first 100 participants right after they signed up to get their experiment kit.

I have grouped the questions by topic, and you can easily navigate to them using this menu:



1. Where do I send the information?

When you get your kit in the mail, there will be a paper guidebook that will walk you through each step of the process, including where to send the information.

2. Does it matter how deep they are buried?

Yes! Please bury the simple science kit fabrics about 3” underground, and the fabric book should be about 3-5” underground. All this info is in the guidebook.

3. Any specific area in the yard I should bury the swatches?

The best place to bury is outdoors in a spot that has access to rainwater. The best spots might have lots of juicy worms nearby. But ultimately, the randomness of this experiment is what makes it realistic.

4. Can one bury the materials in dirt in houseplants?

For this experiment, I ask that everyone plants their fabrics outdoors in an area that has access to rainwater. For proper biodegradation, there should be other biotic organisms present, and I don’t think a pot indoors will suffice.

5. Is there anything you would like to see included?

Yes! When you upload your photos, I’ve made a spot for you to include field notes about anything and everything you might feel is relevant. When you choose your spot to bury, what is the soil like, what is the access to water, what is your climate like? When you dig up your fabric, describe with words how it feels and looks. Add any notes about things that might not have gone according to plan, or any expectations or thoughts/reflections that you had along the way.

6. What do we submit if there are no scraps remaining to photograph?

I have a hunch that this might be the case for some people in week 6 or 8 in the simple science version. It will take some really careful digging around in these weeks to make sure you aren’t missing anything, even the tiniest bits of fabric that might be left! If you come up with nothing then- first of all, THAT’S AMAZING! But I think it’d be fun to play around with creative ways to submit your photo—an empty hole? A blank photo sheet? A bug instead of linen? I’ll let you guys decide what to do here 😊




1. How many folks are participating?

I am hoping to recruit at least 100-150 participants for each version of the experiment, but hopefully the word gets spread and many more sign up! The more data, the better. As of this moment (6/15/23), there are 105 participants signed up in total.

2. I'd love to learn about where in the US you have people doing this. Are we evenly spread? :)

The plan is that there is no plan 😊 I really am happy to get participants from anywhere and everywhere in the US! After just one week of recruitment for the project, I have participants registered from 34 states! So far so good.


3. Do you send out other types of fabric to test?

I considered it! I of course am curious to see what happens when you plant a synthetic fabric like polyester, although I think we can safely assume that nothing will happen—plastics usually take hundreds of years to start to break down. But I also figured it’s probably irresponsible to ask hundreds of people to put plastic into the ground anyway! I wanted to keep it relatively simple for our first year, but next year I think it’d be fun to do a linen vs cotton vs rayon/Tencel/bamboo fabric test!

4. I have lots of linen scraps. Would it be useful to see whether or not there is a difference in natural vs commercially dyed linen?

I TOTALLY want to know the answer to this question!! I am considering doing it as an experimental condition in future iterations of this project. If you want to try it this year, give it a go and share the results with us in the fb group!

5. How might the embroidery/using other materials affect how it biodegrades? For example if we use material that worms may be more attracted to, will that skew the data?

I absolutely LOVE thinking about worms having tastes for our threads and I need this illustrated or animated or something. In all seriousness, maybe probably yes? I don’t think skew in a bad way, but just a fun thing to consider!

6. Will polyester threads survive differently than cotton or silk thread? What would happen if I used cotton threads instead of linen?

Great curiosity about the polyester threads! My guess is that polyester threads would not biodegrade at all, and cotton/silk would biodegrade but at a slower rate than linen thread. My fabric meditation book peeps will be using linen thread, which I’m curious to see if it will biodegrade as quickly as the fabric (my guess is no bc it’s denser??) I also do not know (and am not sure if it is made public) what additives might be on cotton or linen thread to increase their durability.


7. What differences do you think you'll discover from soil samples from a wide variety of places? Do you have reason to expect a large variation in how long it takes to degrade in different locations /soil? What is the existing data?

I’m so interested to find this one out— I’d consider myself to be moderately educated on ecology, but honestly not too much about soil science. I bet there are some people in this group who could make much better predictions than me! My guess is that our participants in dry/arid climates this summer will have slower biodegradation, and those that get a lot of rain will have faster processes. But I can’t say much more than that. Like what about clay vs black soil??

8. Will you be collecting any data e.g. zip codes to help determine this?

I planned on collecting city and state… but now I wonder if zip code is more precise? I might add that!

9. I would love to see a map of the locations! I'm a chemist in a former life and would love to help if you need support!

Yes I would love your help!!! I’m definitely going to want assistance from those of you who have more insights on soil science!


10. I want to be kept updated during the process and the results = very curious.

Lucky for you, I can’t wait to share the results!! Look for process and results content in these three places:

  • Read the S2D email newsletter that you’re already signed up for

  • Join the S2D Facebook group (private, open to participants only)

  • Follow @Charli.e.Darwin on Instagram

11. I am curious how the data will be processed and used? Will you be sharing results of your experiments? Will results be shared worldwide?

TBH I’m still kind of curious about this too! Right now, my plan is to first optimize the database on my website so that it can be sorted really well by location, date, experimental version, etc. Because this is visual data collected by the community, it is less about the cold hard science and a little more about the story that it tells. I plan to promote the results on my website, blog, and social media. But I’d also consider avenues for reporting it such as YouTube, other people’s blogs, news outlets and even an academic journal article. If you are someone who is good at writing, storytelling, social media, photo data analysis, etc, and would like to contribute content to for the project PLEASE REACH OUT!! This is going to be a big job and I can’t do it alone!

12. How is it applicable to the real volume of clothing in the waste stream? What about the small surface area of a 2” square of fabric compared to the volume and reduced surface area of a garment?

Great question! So one reason I’m doing this experiment in your backyards (and not in a lab) is because in reality, our trash (and clothing) isn’t kept in controlled conditions- its on the side of the highway, abandoned on a hiking trail, shipped overseas and piling up in countries that are now burdened with a mountain of our trash. So I’m all for the realistic thinking here. That being said, I chose to do the small squares for the simple science kit because it’s a free kit so I’ve got to be frugal, plus it’s easy to bury/dig. BUT I think it’s going to biodegrade faster than a full shirt or pair of pants would. What I think will be more representative of real clothing is the buried meditation book version of this experiment. They will be stitching several layers of linen together and adding elements like thread and embroidery.

13. Why does this end at 8 weeks? Does linen really biodegrade that fast or will 8 weeks just show the start of it?

Oooooo we will just have to find out, wont we!

Additional resources from Charlie Darwin

14. I'm new to natural dyeing. I'm curious how you dye your linen?

Right now I use 3 different plant-based dyes: black tea, indigo, and cutch. I have a blog post about how to dye with black tea that is really very detailed. For now, I use pre-reduced indigo from Jacquard and Cutch extract from Botanical Colors. Both of those companies have great resources on how to use their products!

15. Do you have scraps available for purchase?

A couple times per year I will add scraps to my website to purchase in larger bundles than you get in these kits. But I’m sort of on a hiatus from that right now since I’m funneling so many of my scraps into this project. I let my email subscribers know when the scraps are available, so subscribe to the general Charlie Darwin email list to get updates!


Have any more questions about this experiment, or want to use your talents to help contribute to its success?

Email me (Leah, the Experiment organizer), at

Or feel free to drop your questions in the comments section below!



Hi there:) I have a question. I am in northern CA where there will most likely be no rain. Will that still be an interesting sample for you or should I not participate? Thanks!

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