Gardeners have different opinion when it comes to using urine in the garden as fertilizer. It is a great nutrient source for plants, but it also has some risks. Not to mention some people are grossed out by urine.
Before we begin, I should let you know that I'm a pro-pee and have been using urine in my garden with great results. That said, some concerns are justified, while others are just hype.
In this article we'll take a closer look at using urine in the garden, then you can decide for yourself if it's gross or great. You'll also learn how to use them.
Now, I have to start the conversation with a look at urine quality. That's because not all pee is equal.
My pee, for instance, is like the fine wine of pee. I eat nearly all organic vegetables that I grow myself. My diet also mostly consists of vegetables and fruit. The meat I do eat comes from our homestead or farmers I've personally vetted.
No antibiotics enter my diet. I also don't take any pharmaceutical drugs (or other kinds either). I'm healthy.
Plus, I drink about 2 gallons of water a day on average because I work outside most of the day. So, I have a good working urinary tract. Oh, and that water I drink is from our well and is about the purest, tastiest water possible.
If you live as I do, then your pee is probably quite fine too. However, if you drink municipal water that is heavily treated with chemicals and contains pharmaceutical residues not removed at the water processing plant, take a lot of drugs yourself, eat a diet that is mostly crap, and barely drink water, your pee likely has more bad stuff in it than mine.
What is In Urine?
One of the main reasons you pee is to balance the amount of liquid in your body. Another purpose of peeing, though, is to eliminate pollution from your bloodstream, isolate it in your kidneys, and then pass it out through urine.
According to researchers, depending on what goes into your body, over 3000 chemicals can potentially come out in urine. Some of these are metabolites created by bacteria, others come from your body and are pretty harmless. But roughly 2200 of those chemicals come from cosmetics, food, drugs, or environmental exposure.
So, if you have a lot of toxic things going into your body, then you likely have more toxic things come out in your urine. In a healthy homesteader, though, putting mostly good stuff in, the stuff coming out is primarily water and excess nutrients that the body doesn't need.
Reality Check on Pollutants in Urine
Truth be told, even if your pee isn't the fine wine of pee, it's probably still safe to use in the garden. First of all, if it comes out in your urine, then guess what? It's already going into your body in the first place. Putting it back in your garden isn't going to significantly increase your risks.
Also, when you put it on your garden, the soil will process some of that toxicity in the way your kidneys do. Soil is naturally a pretty good biofilter. That's why it is frequently is used in many applications to clean water, air, and eliminate odors.
The EPA's Opinion
Also, according to the EPA, there's no reason to believe that plants will uptake any of the toxic man-made chemicals that might be in urine. The EPA is so certain that this is not a risk, they even allow farmers to apply minimally processed sewage materials (called Class B Biosolids) to fields that grow food. These biosolids contain urine from everyone who flushes in cities, along with poop, medical waste from hospitals, run-off from agricultural applications, over-fertilized lawns, road pollution, and more.
Now, I personally have reservations about Class B Biosolids because what enters the sewers isn't just urine or manure from healthy homesteaders. But, still, the fact that city-scale stuff is considered safe to use in large amounts for large scale farming, make me feel like using my own urine might not be that big of a deal.
Possible Risks in Using Urine in the Garden
In general, urine poses very few health safety risks at all. However, there are a few things I came across in my research that might make you think twice about using urine. Here's what I found.
There are a few illnesses that are known to be transmitted by urine. Only the first one on the list below is directly linked to transmission by urine coming into contact with soil.
Leptospirosis is an infection caused by bacteria that is transmitted by urine. The urine usually comes from animals and is transmitted to humans through contact with soil or contaminated water.
Livestock, pets, rodents, and other wild animals are the primary sources of transmission. However, humans also shed leptospira bacteria in urine if they are infected. So, if you are infected and use your urine in your soil, you might increase the volume of leptospira bacteria in your soil. Those bacteria can live in soil for weeks to months.
According to the CDC, there are between 100-150 cases (out of 327 million people) of leptospirosis in the US each year. About half of those occur in Puerto Rico. So, the actual risk of being infected with the disease is very low. But, it's still something to think about relative to using urine in the garden.
– Cytomegalovirus (CMV) Infection
Cytomegalovirus (CMV) infection is the most common disease that can potentially be transmitted by urine. Symptoms of CMV may be confused with mild flu or sometimes mono.
Generally after infection, the CMV goes dormant and the host has life long immunity to it. While this is a risk, given that it already infects most humans at some point in their life, and most of us develop immunity, the risk seems small.
– Urinary Tract Infections (UTI)
Urinary tract infections or UTI's are caused by bacterial infections from things like some forms of E. coli or Citrobacter (from hospital caused UTIs). Most UTI causing bacteria are already ubiquitous in nature, reside in our intestines, or are prolific in hospitals.
Also, there is believed to be a minimal risk from them in urine. I couldn't find any links between urine in the garden and UTIs. Personally though, I'd skip using urine in the garden while I had UTI symptoms, or for a while afterward, just to be safe.
Medications designed to treat bacterial or fungal infections such as antibiotics or antifungals can also negatively impact the beneficial bacteria and fungi in your soil. Skip using urine that may inhibit the beneficial life in your soil.
Any bodily fluids from patients having chemotherapy or radiation are potentially dangerous. They can pose risks to septic tanks, caregivers, and more. So, keep this out of the garden.
Even drugs like sleeping pills and anti-depressants can pose environmental risks to wildlife. So it's better to avoid using urine that may contain pharmaceutical residues in the garden for the safety of wildlife.
5 Reasons Why Urine is Worth the Risk
So, now that you know the primary risks, why should you even bother with using urine in the garden?
Well, for starters, it's nature's perfect fertilizer.
1. Nutrient Powerhouse
Urine is about 95% water and 5% other stuff. Most of that other stuff is urea, which is the most commonly used nitrogen fertilizer on the planet.
Most of the urea used in agriculture today is synthetic. But it's the same stuff that comes out ready-to-use in your urine.
Urine also contains phosphorous and potassium, plus whatever other excess trace minerals you eat that your body doesn't end up using.
2. Immediately Usable by Plants
The thing that makes urea the most common nitrogen fertilizer is that the nutrients are in a form that can be immediately used by the plants. In other words, the urea in urine is fast-acting.
Fast-acting fertilizers shouldn't be the only source of food for your plants. But, when you have a nitrogen deficiency or if you want to expedite production in your garden, urea is the perfect answer.
3. Free Fertilizer
Synthetic urea is one of the most used fertilizers because it's also one of the cheapest to buy. However, when you use urine in the garden at home, you get an even better deal.
Your urea is totally free!
4. Constant Supply
The other great thing about urine is that you have a constant supply. What goes in, must come out. So, water in, urine out. As long as you keep drinking water – which you should do for good health anyhow – you have a constant supply of plant-growing urine.
5. It Works!
Free, and readily available are great reasons to use urine. But also, researchers have discovered vegetables grow even better with urine and a bit of wood ash then they do with commercial fertilizers.
Bigger beets, more productive cucumbers, giant cabbages, and terrific tomatoes can all be had using your own urine! Testing also shows the nutrients in urine-grown vegetables are equal to vegetables grown using more conventional approaches.
Plus, in blind taste tests, urine grown veggies were indistinguishable from conventionally grown veggies. So, in case you were wondering… No, you can't taste the urine in your veggies.
How to Use Urine in the Garden
Now that you know the risks and benefits, there are a few tricks to using urine in the garden.
Tip 1: Fresh is Best
Fresh urine doesn't stink. But as bacteria begin to break down the urea into its constituent parts, odors come as a result of that decomposition. Urea is broken down into ammonia, which of course smells like… ammonia.
If you use urine fresh though, the bacteria don't have time to act so very little ammonia is released.
Don't go saving your jars of urine. Instead, use them immediately or direct apply.
Tip 2: Dilute and Don't Pollute
Urea is a very strong fertilizer. So, it needs to be diluted. The urea in urine is already diluted by about 95%, but it needs to be diluted by about 900% total to be safe for use as a natural fertilizer.
Basically what that means is that you need to add about 8 times more water than what's already in your urea before you use it in your garden. If you have a cup of urine, add a gallon of water. This is basically the same ratio you use for passive compost tea.
Tip 3: Keep It Simple
I have a 32-ounce sour cream container that I keep outside my back door. When I need to go, I step out back and use the container. I don't put a lid on the container so I don't trap smells.
When it gets full, I take the container out to the garden, pour half of it in a 2.3-gallon watering can almost full of water. I stir it gently with a stick. Then, I go water my plants.
Tip 4: Don't Apply To Edible Plant Parts
I personally don't use urine for lettuce or other come and cut greens. I densely plant those to keep out weeds. So, because of the way I plant, I can't water the roots of the plants without hitting the leaves of the plants.
I also don't use it on above-ground parts of root vegetables such as beets, turnips, and radish. When those storage roots start to form, I stop watering with diluted urine. They don't usually need the extra nitrogen at that point anyhow.
I'm not really worried about safety or even flavor. But I know there is a yuck factor, particularly if you serve what you grow to others. So, I just steer clear of the edible parts for everyone's mental comfort.
Tip 5: Direct Applications
There are also times when you can directly apply urine without dilution. For example, I do this with my established perennial plants. I squat and pee toward the outer perimeter of the plant root zone.
All of our plants are mulched. So, the urine usually spreads through the mulch a bit before it starts to filter into the soil. I suspect this eliminates the risk from nitrogen burn because I do this regularly and my plants seem to love it.
My circuit of trees, fruit bushes, and herbs I visit in rotation. My visits are spaced out by 3-4 days, so no single plant gets overloaded. Honestly, this is so effective that for my pee-fertilized plants, I don't do much else to add fertility besides occasional mulching to keep the soil from being bare.
Tip 6: Compost It
If you are still worried about using urine in your garden, then compost it. Urine is a great activator for a stalled compost pile. Or, you can just dilute as described above and use it to water your pile.
The process of composting and aging will minimize the risks of pathogens. Most of the nitrogen will be converted to ammonia and be lost to the air. But, the trace minerals will remain in your pile. So, at least not all of the good stuff in your urine will go to waste.
Conclusion to Using Urine in the Garden
I know it's kind of taboo to talk about pee in public. But really, by not having these conversations, some of us are sending really beneficial stuff down the drain. Then, we have to spend more time and money to create more complicated forms of fertility to grow our food.
Yes, there are some potential risks from using urine in the garden. Really though, our whole lives are riddled with risks. I always wonder if I am going to catch a cold every time I push a grocery cart or open a door in public in winter. I worry that I'm going to get norovirus every time I eat at a restaurant.
But, I simply don't worry about using my urine in the garden. I know the quality of my urine. I am conscientious about how I use it. It saves me money and time while helping me become more self-sufficient.
So what do you think? Is pee an excellent, free fertilizer? Or will you save it for your Bear Grylls wilderness survival adventures?