Pee is an effective, free, and safe fertilizer for all plants—Here’s how to use this “golden water”
Did you know urine is a safe and free nitrogen fertilizer suitable for all plants and a great compost activator? The microbes in soil can break down its compounds effectively. Plus, pee doesn’t smell when diluted correctly.
Using pee as fertilizer: for plants and compost
Are your plants in need of a growth boost? When diluted with water, urine works as a nitrogen fertilizer for all indoor and outdoor plants, as well as the lawn. It’s important to stop fertilizing woody species and edible plants well before harvest time, but you can keep fertilizing summer flowers into September. You can also use urine as a household composter activator or as a nitrogen supplement for leaf compost. If properly diluted, pee does not smell.
Recycle nutrients and conserve water
Urine is an excellent fertilizer because it contains 0.2–0.9 percent nitrogen, along with phosphorus and potassium in a form plants can easily use. Collecting urine is also a great way to lower your water bill and reduce the burden on water treatment facilities.
Dilute pee generously
The amount of water you need for dilution depends on the plant species, its size, the soil’s moisture, and how often you apply it. Because urine contains salts, overuse can increase soil salinity. Particularly in the case of small seedlings, potted plants, and chlorine-sensitive species like tomatoes, potatoes, and cucumbers, you should dilute urine with ten times the amount of water. Use the same 1:10 ratio if the soil is dry.
Use it fresh or store it
You can apply urine as a fertilizer fresh or keep it in an airtight container. In an oxygen-free environment, the urea in urine converts into ammonium nitrogen, which plants can readily absorb. Meanwhile, the urine becomes alkaline, which destroys potential pathogens. You can store pee in a cool place for up to six months or at room temperature for a couple of months. The same shelf life applies to urine from a dry toilet.
Pee is a safe fertilizer
A Finnish study found no issues that would limit the use of urine as fertilizer. Soil microbes effectively break down any compounds or medications in urine. You can avoid odors by rinsing your collection container after use and letting it dry upside down.
Sources: Senior lecturer Eeva-Liisa Viskari, Tampere University of Applied Sciences
Viskari, E.-L. et al. 2017. BIOUREA. Erilliskerätyn virtsan lannoitepotentiaali, kokeelliset tutkimukset ja elinkaaritarkastelu (The fertilizer potential of separately collected urine, experimental research and life cycle assessment)
