Guest post by Natalie Levin
Composted manure, blood meal, bone meal, and fish emulsion are popular soil amendments. We routinely use these materials in our gardens. But consider adding your own menstrual blood or urine to your watering can and suddenly you might be a pervert. Despite this double standard, I maintain that using one’s own body fluids is safe and arguably less gross than using those of other animals. It’s also more sustainable and compatible with the idea of a garden being a peaceful place of harmony with living things.

Photo by Christine Matthews
The sacrosanct status of animal waste in gardening is a product of colonialist farming systems. Human cultures around the world have traditionally used a wide variety of materials from plants, human waste, and other animals as soil amendments. Those who domesticated large ungulates as livestock came to rely heavily on their manure, but this practice was never universal. Prior to European colonization, slash and burn or swidden agriculture was predominant in the Americas, where animal domestication was far more limited. Reliance on farmed animal byproducts as a primary fertilizer is a European tradition, enshrined in organic farming principles by the European and white American founders of the movement.
It takes for granted that domesticated animals must be at the center of any farming system, bred in large enough numbers to produce massive quantities of waste. In fact, there is no need to filter plant matter through animals to produce fertilizer. Animal agriculture is a significant emitter of greenhouse gases and the leading threat to biodiversity. There is an acute environmental need to shrink the industry, which has spawned a rise in reducetarian and plant-based dietary movements. And yet, products from animal farms, slaughterhouses, and industrial fisheries dominate the organic fertilizer market and gardening lore. When gardeners purchase these soil amendments, we are investing in an unsustainable industry. We might think that we are merely using up waste, but, in fact, the meat industry relies on marketing every part of the animal in order to remain profitable. Why cut back on hamburgers only to sprinkle cow blood on the garden?
Every garden hosts at least one animal who produces free nitrogen-rich soil amendments, and that is the gardener. Humanure is an obvious stand-in for livestock manure, but, first, you have to compost it yourself under specific conditions in order to kill off harmful pathogens.
Urine is easier and safer to use and can be poured into the soil right away, diluted with about 10 parts water. It can also be added to a compost pile to speed up decomposition of carbon-heavy brown material. The same applies to menstrual blood. All three of these human waste products have been used in agriculture by people around the world, including in modern industrialized farming. Humans generally do not produce enough waste for it to be the primary source of agricultural fertilizer, but it can go a long way in a garden, especially when combined with composted kitchen scraps, green manures, or fallen leaves.
The gardening world is slowly moving beyond chemical fertilizer and composted manure as the go-to soil amendments. For those who have the forethought and space, compost piles are increasingly popular. Composting toilets are becoming somewhat more popular and urine fertilizer is reaching the edges of the mainstream gardening world. It’s still considered a kooky thing to do. And when it comes to using menstrual fluids, ancient taboos persist about its supposedly negative powers. The occasional brave TikTok hippie who shares her menstrual gardening secret is met with barfing emojis and may worry about it killing her plants or scaring away partners. Articles on the subject recount fearful experiments and concerns about the dangers of bacteria. Those who support the practice tend to give it outsize credit as a magical elixir. But its nutritional profile is the same as slaughterhouse blood. The difference is that this is free.
In my view, it makes no sense to think that purchasing the blood and waste of farmed animals is preferable to flushing our own blood and waste down the toilet. Though, when it comes down to it, none of these amendments are necessary. You can have a lush garden using composted kitchen waste, lawn trimmings, comfrey, and other green manures. But if we’re going to use animal-based fertilizers, why not use our own? It costs nothing and wastes less. And it doesn’t contribute to the unsustainable industry that produces livestock manure, blood meal, and bone meal.
Given the rising cost of fertilizer since the war in Ukraine started, composting human excrescences may get a second look. My concern would definitely be the danger of pathogens (like Covid for example), since not everyone is likely to be diligent in composting their stuff, if they are doing it as individuals. Maybe a partnership between municipalities that collect sewage and a regulated composting facility? I also believe I read that WA state is considering allowing the composting of human remains, as a green burial alternative.
My ex-husband used to “donate” urine that we used on my allotment site. As a woman, it’s a bit more challenging to collect the urine, but I have been thinking about adding it to the compost bin at my new home.
We’re long past the point where central authorities can be relied upon to properly compost human waste. Much better for people to take personal responsibility and grow as much of their own food as possible and fertilize with nutrients that would otherwise go to waste. I certainly don’t need “Big Brother” telling me I’m not capable of composting waste materials myself.
There’s a group here called the Maine Organic Farmers and Gardeners. They host a huge fair in late Sept. – no flush toilets, only outhouses. They compost the “humanure” to put on fields and orchards. They’ve done this since moving to their permanent location in 1996. I’m sure many think only of the “ick” factor. Why human poop is ickier than cow is something I can’t quite fathom. More power to those who do it right.
in the 1970’s Milwaukee sold a product called Milorganite which was made from composted city sewage. I have seen it a few years later not sure if they are still selling it, but its worth trying to find out.
Milorganite is still widely available, at least here in the Midwest.
Milorganite is one of several bio-solid fertilizers that contain PFAS – Forever Chemicals that have contaminated much agricultural land. https://www.washingtonpost.com/nation/2022/04/11/pfas-forever-chemicals-maine-farm/
Incompletely composted animal manures are a source of human pathogens, not exclusively Escherichia coli and Salmonella as well as others. When you work with human waste, the list of potential pathogens gets longer. Unless you can be 100% assured that your compost has been sufficiently processed, no unprocessed animal or human waste should be used on any fresh fruit or vegetable (typically eaten raw), that may come in contact with the soil. That is the rule for both Good Agricultural Practices (GAP) and the Produce Safety Rule, FSMA.
Enjoyed your perspective. Wish there were more people supportive of this.
Urine has the added benefit of marking your territory, thus potentially keeping unwanted cats, dogs etc from dropping in.
Hahaha. Yes! I wonder if I can keep my neighbor’s outdoor cat out of my garden beds if I mark them myself?
Human waste flushed down the toilet does make it to compost in a more industrialized setting at wastewater treatment plants. There they are able to control the process to kill pathogens and provide a compost that is safe to handle by gardeners. More and more cities are moving towards reusing their biosolids (the technical term for this) for land application instead of simply disposing them off in a landfill.
Maine just outlawed this because of the PFAS
No idea what veg growing needs but flower gardens probably don’t need additional fertiliser if the beds are mulched with the cut foliage in autumn or winter. Over fertilising is not good.
Regarding PFAS, there is promising research being done that shows that fungus can be used to break these down. This is in early stages, but maybe someday it will be used successfully.
Considering that the amount of blood shed in a menstrual period is 2-4 tablespoons, it would not seem to add much as a soil amendment. The exception might be at the beginning of menopause, when it appeared to be shed in buckets, although that was more of an illusion than reality..
Thanks for bringing this up. In fact, I never considered this option from the word at all, although it seems to me that the biological fluids in animals and humans do not differ very much. This seemed like a strange idea to me at first, but as I read the article, I realized that this is also possible and there is nothing terrible about it. You have broken the stereotype. Thank you.