Bat Guano Fertilizer: Using Natural Bat Poop In The Garden

Bat guano – or bat droppings – is used widely across the United States as an organic fertilizer

Guano deposits are generally obtained from fruit and insect-feeding bat species. 

bats hanging upside down. Bat poop is an excellent organic fertilizerPin

Since the United States is home to insectivorous bat – the bat species which feed on insects and roost in bat caves, we easily find fresh guano and large colonies across the country. 

The high nitrogen content of this natural fertilizer makes it the first choice of gardeners for plant growth. 


Even though bats are often regarded as a disease-carrying mammal, their excrement is a fast-acting soil enricher and guano, particularly, has been considered a revered fertilizer by older cultures in South America. 

In the 1600s, the Incas had such high regard for guano they would sentence the person found harming a bat colony to produce it to death.

Often dubbed as super plant food, guano is rich in essential plant nutrients such as potassium, nitrogen, and phosphorous

These three nutrients are essential for vigorous and verdant plant growth. 

In simple terms, guano fertilizer is made from bat poop or guano piles.

The natural fertilizer contains microorganisms acting as natural fungicides and fights against a variety of fungal diseases. 

Bat guano coming from fruit-eating bats has a high phosphorus content aiding in root growth and flower development.  

Best Fertilizer For Cannabis

Guano, the accumulated excrement, and remains of bats and seabirds is a plant superfood that has been in the fertilizing industry since the 1870s. 

Then, as seabird guano, it was mined on the islands off the Peruvian coast and traded to Europe. 

Bat guano is also used as a high-performance organic fertilizer for growing cannabis. 



There are two ways to use bat guano; either in its dry form or as a foliar spray. 

Guano is mostly preferred because it is an organic fertilizer and reduces the risk of nutrient burn.    

How To Fertilize Cannabis

As discussed above, add dry guano to the soil or make a tea to feed your plants regularly. 

Many horticulturists prefer making tea as this step ensures you’re able to control the amount of guano tea you inject into the plant. 

There are different types of bat guano available in the market, including Mexican bat guano, Jamaican bat guano, and Indonesian bat guano, so buy the one meeting your particular requirements.

If you think Bat fertilizer is strange check out Tacca Chantrieri the Black Bat Flower

How To Make Bat Guano Tea

Making guano tea is not a complex process. 

Prepare it by mixing a cup of bat dung with a gallon of water. 

Then, allow the mixture to sit overnight. 

Now, strain the tea and apply it to the plants. 

Here is a step by step procedure to make guano tea.

  • Mix around 3 tbsp guano to 1 gallon of chlorine-free water
  • Use 4 parts cold water and 3 parts warm water to dissolve the bat pellets. 
  • Be careful – DO NOT use hot water
  • Add guano to the water while simultaneously stirring the water
  • Leave the mixture and let it set for somewhere between 8 and 48 hours.
  • Now, cover the mixture while adding air holes, if necessary
  • Feed the mixture to the plant at least 3-4 times a week.

Why Is Guano Good for Cannabis?

Guano is quite beneficial for plant growth. 

It plays an important role in improving the texture of the soil. 

If the soil is too loose, use bat guano to bind it better and increase its water retention. 

In the same manner, if the soil is too dense, bat guano will help you loosen the texture of the soil so the water can penetrate more effectively.

Guano is also quite effective in flushing toxic elements from the soil while simultaneously protecting the roots microbially.  

This organic fertilizer also plays a crucial role in ensuring the healthy decomposition of exhausted material. 

When it is added in compost, it speeds up the composting process. 

Since it is a slow-release fertilizer, it will provide nutrients to the plant for most of its life. 

It is a natural fungicide against chitin and effectively tackles nematodes.

However, one of the drawbacks of using bat poop as a fertilizer is it is a host for the fungus Histoplasma capsulatum which causes the respiratory disease ‘histoplasmosis’ which often results in death of humans. 

In addition, the guana also attracts pests such as cockroaches which are also responsible for spreading potential diseases and secondary infestations. 

However, if you want to use bat poop for the feeding of your plants, make sure you get it from a reliable source and don’t use bat droppings you find in your attic, etc.  

Consult with a professional to better understand how to use bat poop for gardening.