Check out my new book!

“A Publishers Weekly top ten pick!”

A Guide To Safely Using Urine As Fertilizer

May contain affiliate links. Please see my privacy policy and affiliate disclosure.

What if there were a way to avoid chemical fertilizers on gardens, pastures, and orchards? What if that way involved a fertilizer that conserved water, was easily accessible to every single human on this planet, and was absolutely free? The use of this substance is also scientifically backed* as a means to increase production. If you haven’t figured it out by now, I am speaking of using human urine as fertilizer.

Before the “eww!” factor comes into play, let me explain a few things. Feces is the offending element of human waste that is considered unsafe due to bacteria. Human urine is full of nutrients your soil needs. From nitrogen to phosphorous it is a wonderful source of nutrients big and small.

human urine in a sample cup

Is urine sterile?

According to this study:

In our previously reported study (), we used 16S rRNA gene sequencing to demonstrate evidence of uncultivated bacteria in the adult female bladder and we questioned the “sterile urine” dogma. Our current study demonstrates that urine contains communities of living bacteria that comprise a resident female urine microbiota.

So, no. urine is not actually sterile, but it is safe to use as fertilizer in your garden.

Urine as fertilizer: Statistically proven to increase yields

This age-old fertilization practice has been brought back by many looking to harness all of the resources close to them in order to lessen their environmental impact. This has led to research on the practice of applying human urine as fertilizer.

One such study involved smallholders in Uganda and the application of urine at two different concentrations in comparison to a controlled plot. The evidence was clear: “Compared to the control plot, all treatments show a statistically significant difference in yield.”. How much is “statistically significant”? The plot with the optimum urine volume application led to a two-fold production rate of maize over the control plot.

That is significant.

man urinating, from behind

Urine as fertilizer – applying it safely

Safety is, of course, of the utmost concern in fertilizing with human urine, just as it is with animal manure application to improve soil. While urine is considered sterile, there are rare occurrences of bacterial infection that can contribute to bacterial problems around your plants. The solution is simple. If it’s possible that the donor could have a bladder or urinary tract infection, do not take their samples for your garden, field, or orchard.

Along the same lines, the question of how fresh should the urine be is also of utmost importance. In this study human urine was collected and stored in covered containers in the donors’ homes for two weeks in order to protect against pathogens. There is a wide range of opinions on how fresh the urine should be but allowing the urine to sit for a couple of weeks seems the safest of all of the approaches.

The other factor to keep in mind is where to apply this homegrown fertilizer. When using urine as fertilizer, it is generally accepted that applying it to the soil away from the leaves of the plants is preferable. Urine is not applied as a foliar spray, as many organic fertilizers often are, but rather directly to the soil near the base of the plants.

The Ugandan study used the following method: “The urine was applied close to the ground in furrows along the plant rows, which were immediately covered with soil. Besides preventing ammonia losses, this practice helps to reduce the smell and avoid burning crop leaves.” (Kirchmann and Pettersson, 1995)

eggplant in a garden

How much is enough/too much?

The final consideration – and it is an important one – is what volume of urine should be applied to the crops and how much should it be diluted? What is interesting about the Ugandan study is that they cited the urine application as direct and undiluted. Nearly every source out there will tell you that you need to dilute the urine with water at a 10:1 water to urine ratio. And that is what we have historically practiced in our own gardens and orchards.

However, direct application of urine as fertilizer seems to have worked well in a larger field setting where maize – known as corn in the United States – was grown. With no sprawling vines or low-lying leaves, you can see how this application is quite different than a small homestead garden. I think the lesson here is that you don’t want the urine to directly contact the plant at full concentration. If you are doing diverse crops with low-lying foliage, dilution may be your best bet to prevent any type of damage to the plant.

kale growing in a garden

How we collect our urine for fertilizer

The simplest method that we implement on our homestead is to place a bucket outdoors, behind a cove of trees. While the men in the family are working out on the land, this is their designated bathroom spot. Depending on how many bucket-fillers you have in your family, you can harvest a half-bucket full every week or so. Set this aside for garden fertilization.

As I share in my book, The Doable Off Grid Homestead, if you are implementing a bucket system or outhouse:

You can design toilet systems that both men and women can use to help divert the urine into a separate container for use on the homestead. Look online for a little piece of equipment called a urine diverter. It is installed into the box of the composting toilet and can be piped to a removable container that can then be poured off for fertigation.

human urine in a sample cup
*Source: https://www.sciencedirect.com/science/article/pii/S0959652614000948

Click to save or share!

Meet the Author

Shannon Stonger

Shannon Stonger is the founder of the blog Nourishing Days, where she shares her family's journey towards sustainability. She is the author of The Doable Off-Grid Homestead, Traditionally Fermented Foods, and the sourdough baking book 100% Rye. She holds a bachelor's degree in chemistry and lives with her husband, five children, and various farm animals on their five-acre homestead in Texas.

20 comments… add one
  • Dr. Williams Jan 21, 2019, 12:49 pm

    As a health care professional I would strongly disagree with this. Our food that comes from out of our country ie. Mexico has a high rate of E. coli etc due to laborers urinating in the fields. Also the plants use the urine to obtain their juices. Not recommended.

    • Adele Jan 22, 2019, 5:39 am

      E. coli would come from workers defecating in the fields not urinating. Urine doesn’t normally contain E. coli unless the person has a rampant UTI and as Shannon stated, folk with UTIs shouldn’t be donating.
      And I’ve got a degree in biology and am a clinical laboratory scientist so I probably know what I’m talking about. I’ve spent more than my fair share of hours examining urine on a microscope.

      • Ethel M Ebanks Aug 30, 2019, 10:46 am

        You go girl. I even know that E-coli comes from defecating. And I’m just a combat veteran/Mother of 3 boys.

        • NBI Sep 10, 2019, 7:49 pm

          He even calls himself a doctor but he doesn’t know that? Lmao

    • Shannon Apr 1, 2019, 9:41 am

      I have to echo what Adele said in terms of E. Coli. When this has been studied in controlled situations (i.e. they know the urine is clean going on, they know it came from healthy individuals, they know there was no feces involved) they have found it safe. But, I would say, if you have any concerns over the health of the donor, skip it.

  • Josephine Marie Howland Mar 2, 2019, 7:25 am

    Another use for urine in the garden and homestead, is to keep predators away. When we were having bear problems with our chickens, the State fish and game officer suggested that my husband pee around the coop.

    • Kris Bordessa Mar 3, 2019, 12:26 pm

      Good point!

  • Seana Dombrosky Mar 24, 2019, 2:46 am

    Your section “How much is enough/ too much” doesn’t actually state what volumes are safe/ optimal but only covers dilution and making sure that it doesn’t touch the leaves. Does this mean there is no real ideal volume or volume limit?

    • Shannon Apr 1, 2019, 9:53 am

      Seana – Your question is a good one and one that is also hard to answer with hard and fast recommendations. Remember that we are fertilizing the plants with urine, mostly for the nitrogen content. So it is going to depend on what crop you are growing, what the nutrient content of your soil is going into planting, and even how much watering or rainfall you are getting.

      I can only tell you, then, how I practice fertilizing with urine. On our homestead, I use urine as a weekly option for fertilizing. I fill my watering can with a 1:10 dilution of urine:water and I go around the garden once a week and apply it where it seems needed. If there is any sign of low nitrogen – pale leaves, slow vegetation growth – I apply a dose. If there is any sign of high nitrogen, like excessive vegetation growth and little fruit setting, I skip it for a few weeks.

      So it is very much a matter of just paying attention to what your plants currently need, as is the case for a lot of gardening questions. 🙂

  • Really_Old_Guy May 9, 2019, 8:12 am

    I can attest to the wonders of urine applications. I’ve been doing it for some time.

    I skip the ‘wait’ period and simply pee into my watering can, then fill it up with water. The ratio seems unimportant (in my opinion) and I am probably at a 50:1 or 60:1ratio and still getting excellent results.

    I do NOT broadcast to others that I’m doing this…and if they ask why my plants are so huge, I simply say, “If I told you my secret, I’d have to kill you.”

    • Kris Bordessa May 11, 2019, 12:23 pm

      LOL. That seems like an easy solution.

  • Ethel M Aug 30, 2019, 10:55 am

    Being from an Island myself. I can most certainly guarantee the use of urine on fruit trees and vegetables is a win for the plant. My Dad 93 years old at death did this for his plants on Island over 75 years.

  • LM Feb 20, 2020, 4:48 am

    I’ve been using urine both in my compost pile and diluted on my plant soil for many years. It works well. My roses love it. Sadly, there is such a bias against this that I keep the info. to myself. People ask me, “What kind of fertilizer do you use?” I answer, “Oh, it’s organic.” I’ve been using an 8:1 ratio, but perhaps I need to change this?

    • Kris Bordessa Feb 20, 2020, 7:25 am

      I think if 8:1 working for you, keep doing it. (I laughed at your “it’s organic” answer.)

  • Deborah Lamoureux Mar 16, 2020, 8:07 am

    If Human Urine is good for crops, why cant I plant over my leach field? the leach field is the water and overflow of urine not the solids. The solids get pumped out every couple of years. Thank you

    • Kris Bordessa Mar 29, 2020, 1:35 pm

      I guess one problem could be that you won’t know the dilution? That said, in the book Solviva the author talks about how one area of her garden *thrived the year their plumbing failed and they tossed urine out there.

    • Surfer Bob Apr 1, 2020, 8:56 am

      When you think about how a septic or earthship type of sewage treatment system works, you know that the liquids pumped into the leach field have to be saturated with whatever the poop has / had in it (including bacteria). I’m no health professional and I have no data to comment on whether or not the soil above the leach field would also contain whatever the poop water contained. I have looked into earthship systems and they only plant landscape type (not for eating) plants over their “leach field” if you can call it that. Part of their choice for that may be the goal of placating building officials. There are a wealth of things I don’t know. I live in Reno, NV as of June of 2019. I have been saving my urine because I thought it might be a good thing for plants. We have wild horses here that are protected and allowed to crap wherever they want to. In the right season, if I choose, I can collect this crap for fertilizer. I have been pondering the possibilities of modifying an IBC container and filling it with horse crap, my pee and other organics to make some sort of powerhouse compost tea. Any thoughts?

      • Kris Bordessa Apr 1, 2020, 4:10 pm

        Horse manure is an excellent fertilizer. Your compost tea sounds like it could be a great addition to the garden.

  • Su Apr 8, 2020, 9:30 am

    One should consider any medications that may be passed through the urine

    • Harmonia May 24, 2020, 9:06 am

      This is a very important concern. If you are taking any pharmaceutical meds DO NOT USE URINE in your garden.

Leave a Comment