Using Bat Guano (Bat Dung) In Your Garden

Bat guano or bat dung is a fantastic fertilizer high in nitrogen and phosphorus. Learn how to apply it to your garden here.

Bat guano fertilizer ready for a mid-season application


Gardeners use bat guano as a type of manure fertilizer in their gardens. It helps your plants to thrive and become healthier, stronger, and greener. It also helps considerably with flower development.

Bat guano is dried in organic fertilizer form, and you can easily find it in a powder form or as small pellets. When mixed with water, it becomes a slow-release fertilizer with high nitrogen content, helping all of the flora in your garden thrive. 

What is Bat Guano?

Bat guano fertilizer ready for a mid-season application
Bat guano fertilizer ready for a mid-season application. Source: Chiot’s Run

Guano is the excrement of birds that are found near the sea. Bat guano is essentially bat poop harvested from wild insectivorous bats and fruit-eating bats. Several bat species produce resources for companies that make commercial fertilizers and soils, many of which consume cave cockroaches.

In the 18th century, bat guano was used to produce gun powder and was actively harvested from bat colonies for that purpose. In fact, actual bat cave mines were created to harvest the droppings of bats! What essentially resulted was a wealth of guano deposits.

Today, it’s popularly used as an organic fertilizer for plant life. The Organic Materials Review Institute has placed their stamp of approval on mineralized forms of it as a conditioner for your garden soil and as essential plant nutrition for your plants. Once applied, it will improve the growth and structure of your plant. 

Bat Conservation International promotes proper harvesting of guano for sound cave ecosystems, too. While the guidelines they provide in training to guano farmers around the world are currently voluntary, hopefully they’ll become the industry standard. Much like sphagnum peat moss, ethical harvesting from the source (in this instance, the bat colony) is important for keeping the resource in abundance.

Bat poop is also an incredible compost activator as it significantly speeds up the decomposition process. Although it’s a bit expensive, it has a long-lasting positive impact on plant growth definitely makes it a solid investment for all gardeners. 

3 Benefits of Bat Guano Fertilizer

Here are some glorious benefits of bat poop fertilizer:


Bat guano is chock-full of nutrients that are beneficial for the development of your plant. The fertilizer made of bats’ droppings usually comes with around a 10-3-1 ratio of nitrogen, phosphorus, and potassium. These are the three most abundantly used plant nutrients.

The high nitrogen content of bat guano helps your plant leaves become greener in just a few days. This is what makes bat droppings such an effective and useful fertilizer.

The phosphorus in the fertilizer will encourage seed creation and flower development in your plants, while the potassium will feed established plants and help them move their liquid content and nutrients more effectively. 

The slow-release nature of this bat poop fertilizer provides a continuous supply of nutrients to your plants and garden lawn for at least two to three months after the initial dosing. 

Soil Improvement

Bat guano makes a great fertilizer because it contains microbes that benefit the texture of your garden soil. It also has the potential to enrich the soil and improve its draining properties. Additionally, it helps make dense soils lighter and holds together loose soils. 

Plus, guano is not easily washed away from the soil, so it benefits your soil and feed established plants much longer than inorganic fertilizers that are displaced or washed away after a single rainy day.

Microbial Action

Bat guano supplies more than just nutrients to your plants. It also carries beneficial micro-organisms or microbes. Microbes are minuscule single-cell organisms that cannot be seen with the naked eye. The microbes found in bat guano have bioremediation capabilities. 

What this essentially means is that the droppings of bats can remove the toxicity of your garden soil. Plus, these helpful microbes loosen the soil, which increases its water-holding capacity and air space.  

Moreover, these microbes protect your plants by preventing the occurrence of dangerous nematodes and soil diseases. Plus, they are efficient decomposers, so much so that if you want to speed up the decomposition process, simply add bat guano to a compost pile. 

These microbes will break down the dried organic material in your soil and turn it into a source of nutrients for your plants. This will also create a soil texture that will retain moisture without overly saturating your plants’ roots. 

How to Properly Use Bat Guano as a Fertilizer

A cute little long-eared bat
A cute little long-eared bat. Source: Javier Abalos

You can find bat guano in fresh or dried form. Typically, you can buy it in powdered or pellet form. Plants that can benefit from guano includes ornamentals, herbs, vegetables, nut trees as well as fruits. Fresh guano, much like fresh cow manure or chicken manure, can burn plants. Therefore it’s best to use commercially processed guano in your garden.

You can incorporate the guano directly into the soil, turn it into a liquid fertilizer and spray it on the foliage or disperse it through an irrigation system. 

When applied to plant leaves, guano not only produces vigorous vegetative growth but may also protect them from fungal infections. You can use guano as a top dressing fertilizer, either in wet or dried form. Simply mix it into the top layer of your soil prior to planting or during active growth. 

Pro Tip: Always make sure to read the instructions on the fertilizer label before using it. Also, if your plants show any sign of distress, immediately stop using guano fertilizer. You don’t want to burn your plants with an overabundance of guano.

When to Use

You can pour it into the soil immediately prior to planting. This will ensure that your garden soil is sufficiently prepared to provide beneficial nutrients to your plants. 

You can also add guano fertilizer during the active growing season. Simply make potent guano tea and use it during your regular waterings. 

Where to Use

Sprinkle guano powder around the base of your growing plant and water it thoroughly. You can also make guano tea and spray it on the leaves of your plant to protect it from fungal diseases. 

How to Make Bat Guano Tea

The best way to utilize the full potential of guano is to brew an aerated compost tea out of it. To make a potent guano tea, you need to add liquid or powdery guano into warm water, then aerate it with an air pump. However, beware that this tea will produce a severely unpleasant odor. 

Here’s how you can make this beneficial tea:

  1. Pour 1 tablespoon (14ml) of bat guano in 32oz (1l) of warm water – make sure it is not hot as that will kill the microbes in your guano.
  2. Stir the mixture well, and turn on the air pump.
  3. Leave the tea to rest and brew overnight.
  4. Use once every week to ensure generous and fast plant growth.

Or you could follow this recipe:

  1. Wrap ½ cup of guano in cheesecloth and steep it in about 1 gallon (4 liters) of water.
  2. Let the tea steep for at least 3 days before using it as a fertilizer.

You can use this guano tea as a foliar spray and apply it directly to the leaves, or you can pour it over the roots and soil. Bat guano tea is a great source of abundant essential plant nutrition. 

It will also effectively protect the soil from insects and nematodes. Plus, bat guano tea will ensure that your garden soil retains its moisture without harming the roots of your plants.

Last update on 2024-06-19 / Affiliate links / Images from Amazon Product Advertising API

Two rust and black fruit bats hang from the branches of a tree in the garden.


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