Growing With Guano: How Bat Guano Benefits Soil and Plants

By Alan Ray
Published: November 25, 2022
Key Takeaways

Not only is bat guano an amazing supplement for plants and crops, but bats themselves are pretty amazing little creatures when it comes to the ecosystem they live in. Read on to learn more about the goodness of guano.

Brimming with nutrients and high in nitrogen and phosphorus, bat guano can be used to feed plants, amend poor soil, or even enhance the texture and nutritional value of already good dirt. This amazing organic excrement can increase the development and growth of nearly every plant in your garden, greenhouse, or growroom.

But not all bat dung is created equal. Some bat species are frugivores or fruit-eaters. Their waste contains higher levels of phosphorus. Insectivores, of course, eat insects. They tend to produce guano with increased amounts of nitrogen. Read the labeling and choose the one that best suits your growing needs.


Bat Guano is Loaded With Nutrients

bowl of bat guanoThe term 'guano' refers to the feces of bats and seabirds only. Moreover, bats are the only mammal to excrete guano.

Bat guano is filled with nourishing macro- and micronutrients. Macro are the ones plants need in large amounts. Like carbohydrates, proteins, and fats. Micronutrients include manganese, boron, iron, calcium, zinc, and sulfur.

Guano is also rich in nitrogen (N), phosphorus (P), and potassium (K). The numbers you read on a bag of fertilizer refer to the percentage of NPK it contains. In that order. Guano’s levels are generally 10-3-1.


NPK in Action

  • Nitrogen helps promote lush, green growth in plants.
  • Phosphorus aides in flowering and root development.
  • Potassium supports overall good health.

The high nitrogen content in guano is excellent for plants in the vegetative state while the elevated phosphorus levels promote stronger branch development and bigger blooms during flowering. Be careful with this fertilizer on new vegetation or first feedings. All things in moderation. High nitrogen quantities can burn a young plant’s developing roots, disabling nutrient and water uptake.

Guano also makes an excellent fertilizer for herbs, fruits, and vegetables of most every kind. Surprisingly, in addition to its nutritive value to plants, bat guano is also very good for the earth.

5 Ways Bat Guano Benefits the Soil

  • Microbes — Bat guano is teeming with them. These microscopic organisms help detoxify the soil.
  • Microorganisms also loosen and aerate the soil, allowing it to hold more water and creating space for roots.
  • Improves soil drainage from the aeration or creation of space for air.
  • A natural fungicide that helps control nematodes and protects the plant.
  • Accelerates decomposition in the creation of compost.

It also assists in effectively breaking down organic matter in the earth. Guano can be spread on top of the soil and watered in or blended into the soil with your favorite compost. Its addition can be an effective soil booster and texture upgrade. The specifics of how much to use and at what proportion is all available online.

How to Make Bat Guano Tea

spoonful of powdered bat guanoGuano’s many applications in the garden make it desirable for organic growers.

Many growers like to work with guano in liquid form. This is done by creating what is known as a ‘bat guano tea’ which can then be sprayed directly onto the plants or poured at the base. The recipe is pretty straight forward.


You’ll be adding about a tablespoon of dried guano to a quart/liter of warm, preferably unchlorinated water. To make larger amounts, use one cup of guano per gallon (3.78 L). Stir gently into the water until well mixed. Be careful, though. Read a little further before you make this.

Let it sit overnight and apply directly to the plant’s leaves via spraying or pouring onto the base of the plant. Some gardeners expressed that due to the complex structure of guano it may take a week or more before the plant begins to fully utilize the nutrients contained therein. You should be growing strong after that.



Be Careful With Bat Guano

ALWAYS wear a mask and avoid breathing in its dust when handling bat guano. This powdery poop can carry a dangerous fungus called histoplasma that causes Histoplasmosis in humans. Histoplasmosis is a nasty respiratory disease that can be fatal if left untreated. So exercise caution when working with guano in the garden, greenhouse, or anywhere, really. These microscopic spores thrive in warm, moist areas like the lungs, so you don’t want to be unknowingly breathing in those dangerous pathogens.

To the Bat Cave! (not so fast)

Know of a cave or two near you and are thinking of gathering your own guano? Forget it. While mysterious and exciting, caves are extremely dangerous places and not for the inexperienced. And trying to collect bat guano only adds to the danger. Within a dark cave you can get lost, slip into a bottomless hole, break bones, drown, be poisoned by toxic air or, perhaps, meet a friend of Gollum’s.

Ergo, unless you are an experienced spelunker (cave explorer) or on a guided tour, you should avoid even entering a cave. Instead, enter a garden supply center or go online and buy your guano. It’s a lot easier and a much safer option.

Other Ways Bats Benefit Agriculture

bats hanging from a treeIt's important to ensure the guano you use is ethically sourced and harvested.

Beyond their highly beneficial waste, bats are extremely important to agriculture. Actually, to the entire ecosystem. Their dung often contains seeds from the foods they’ve eaten which are air-dropped over the ground in a flyover evacuation. This provides an excellent seed distribution system in a classic symbiotic relationship. Additionally, bats help control the insect-pest population for farmers and city dwellers alike.

One report suggested a single bat can eat up to a thousand mosquitoes in one night. Others say a few hundred and that sounds more feasible but if they eat just one, it’s a better world already.

Here’s another plus. Were you aware that more 300 species of fruits rely on and are pollinated by bats? The list includes mangoes, avocados, and bananas. Bats exclusively pollinate the Agave plant which produces tequila. So-no bats, no tequila. Caramba!

6 More Facts About Bats:

  • There are some 1,400 species of bats worldwide.
  • About 45 bat species live in the U.S. and Canada.
  • Some bats can fly more than 100 miles per hour (160 km).
  • Chiroptophobia is the fear of bats (don’t we all have that?).
  • Around 80 medicines are produced from plants that depend on bats for their survival.
  • Baby bats are called pups while a group of bats is known as a colony.

As you may have surmised, bats are amazing little creatures and great for the environment in a wealth of ways. From their critical pollination of some of our favorite fruits and crops, to helping control the insect population. Add to that their gift of the golden guano and ours is a much better world with bats in it.

So if you’re looking to turbo-charge your favorite foliage, you’ve found the perfect fertilizer. Not only are you going to love the results, your plants are guano love you for it.


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Written by Alan Ray

Profile Picture of Alan Ray

Alan Ray has written five books and is a New York Times best-selling author. Additionally, he is an award-winning songwriter with awards from BMI and ASCAP respectively. He lives in rural Tennessee with his wife, teenage son, and two dogs: a South African Boerboel (Bore-Bull) and a Pomeranian/Frankenstein mix.

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