Urine Does a Plant Good

Photo by Andrew Scott

Let’s talk about #1 (aka pee pee, urine, pee, or urea) and #2 (aka poop, poo,or  sh*t) .  Frankly, #2 gets alot more attention.  We use the word to express our unhappiness, when we bang into something, or drop something on our toes.  (No maybe that is the “F” word.) We say things like “you think your sh*t doesn’t stink.  Even UPS’ uniforms are brown. Plus, it has presence.  You definitely know when it is around since it smells for goodness sakes. Even I have been known to talk about poop especially when it comes to the quality of recycled toilet paper.

On the other hand, #1, pee, or urine really gets very little attention.  Who cares about the yellow mellow stuff?  Plants.  They love it and we produce a lot of it. Some more than others. How come?  Read on.

According to the Washington Post article,  “Human Urine Safe, Productive Fertilizer,”

“Urine is a valuable fertilizer which poor people could use to increase yields and not contaminate their environment. It is a resource, not a pollutant, if correctly managed,” said Helvi Heinonen-Tanski, leader of a research group at the University of Kuopio’s Department of Environmental Sciences in Finland.

Before you start with the “ewww” and that is disgusting, the above noted research group decided to compare  a nitrogen loving cabbage crop feed urine fertilizer versus a crop without .  What they found is as follows:

” At harvest, the cabbage enriched with the urine had several advantages: It was slightly larger, it grew to its maximum size more quickly, and, for most of the growth cycle, it suffered less bug damage than the commercially fertilized variety.

Cabbage from all three plots was made into sauerkraut and taste-tested by 20 panelists. Each type tasted different, but all were rated “good,” the study said.”

Heck, if I had known this I would have had my boys urinate all around my cabbage, cauliflower and broccoli. I hate those cabbage loopers. Kill the buggers.

Urine studies are sooo fascinating.  Why not find another purpose for urine other than tricking people that it is shampoo? (Yes, we tried to do this as kids.)

A 2009 Finland study reported in an ABC News article found that tomato plants  fed urine and wood ash from a fireplace  produced a bumper crop with no noticeable difference in taste from other tomatoes.  Urine contains nitrogen, phosphorus, potassium, calcium and magnesium.  The  wood ash helps to reduce the acidity of the soil.

“But the Fins say they are the first ones to combine urine with wood ash, and plants treated with that substitute performed four times as well as unfertilized plants and left the soil less acidic. The scientists insist it’s safe and doesn’t pose “any microbial or chemical risks.”

According to the article, human urine packs a punch in which a single human could fertilize about 6,300 tomato plants,which in turn would produce 2.41 tons of fruit in just one season! A word of caution, before you send junior or hubby out to the garden, human urine can carry pathogens if a donor is severely infected.

“But most pathogens can be inhibited or killed if the urine is stored for one to two months,” Prahan said. Urine contains urea, which turns into ammonia in a few hours or days, which kills pathogens, Prahan added.”

Now, if you are going to do the ready aim fire bit, here are some words of advice from the article. Urine should be stored in a jar or other suitable container for at least a couple of months so that it naturally immobilizes any pathogens. I wondered if you have to keep it in the refrigerator or not? In any event, never spray it directly on the plants but rather around the plants and rake it into the soil.  Who said being green wasn’t cheap?

Who would have thought someone would develop a homemade solution on how to make pee into fertilizer? Brita and  Rebecca developed a kit, which is no longer being sold since “our lawyer has advised us not to sell the kits anymore and so we are taking a break from producing them while we think this through. The liability of making these chemicals available to other people is high. This is one of the interesting predicaments that we find ourselves in as bioartists.”

See the below Planet Green video featuring the kit.

Oh, by the way, April 17 (2 days after tax due date) is Pee Outside Day.  See here for more information on  how you can participate. (update: The site is no longer up.)

Guess what? There are toilets to separate #1 and #2.  Want to learn more?  Read part 2 of my post on how your toilet might power your house and help grow your plants.  Now, I call this eco-tasking.

Gardener's Supply Company

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  1. 7


    I used urine for the first time this summer on my tomato and cantelop plants and WOW …my tomato plants are almost 5 ft. tall and cantelops are growing like crazy….I mix 1 part urine to 10 parts water and pour around the base of the plant…twice per week.

    • 8


      Norman, I have four boys who would gladly donate their urine. I am a little worried about putting urine on my plants. It is more of the ick factor. Trees–no problem. Anna

  2. 11

    pi..er says

    Pour the urine around the base is the best way. I’m concerned about the temperature causing harm to the leaves if directly sprayed on. I can’t store it for a few months so I use it right away. My Gardenia looks healthier—-green oily leaves. I also work the dog crap into my soil with the water hose. Peeing in a plant waterer saves money on the water bill too. Too many wasteful gallons get flushed.

  3. 13

    Amir says

    normally I go out to pee in the garden, every time in a different spot.
    I haven’t tested the efect on the plants, but one thing for sure: every time I pee in the garden, saves about 3-4 litres of fresh water that otherwise would be used to flush the toilete.
    So thats about 20-30 litres per day and thats good for the planet.

  4. 15

    Betty Harwick says

    Save money by growing your own food, save money on fertilizer, save money on utility bills by not flushing good water down the tubes. Win. . .Win. . . Win. . . Where else could you triple your profits like that!


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