Growing cannabis with bat guano

Growing cannabis with bat guano
Miguel Antonio Ordoñez

Check the guide and learn how to reap the benefits of organic bat guano, offering optimised support for your plant and natural tasting bud.

In simple terms, "Bat Guano' is just bat faeces. The guano of bats that consume fruit or insects are often used by horticulturalists because it can have many beneficial properties for the soil and your plants including:

  • Fertiliser
  • Inoculant
  • Fungicide
  • Nitrogen fixing
  • Compost activation
  • Nematode regulation

Guano is also packed with beneficial bacteria because it contains huge amounts of "Fauna". Fauna is decomposing microorganisms which work on the organic materials in the faeces.

Bat guano is generally preferred because it is organic, meaning it can produce a more favourable taste in the finished product than chemical fertiliser. It also reduces the risk of nutrient burn compared to chemical fertiliser.

The same chemical-free concept applies to organic vegetables. They are more expensive than non-organic because they are considered to have a better taste.

Bat guano gets to work in the soil quite quickly and doesn't produce much of a smell. Another reason guano is favourable is that it can be used during planting or while the plant is growing.


Add guano to the soil dry as a slow releasing fertiliser or make a tea so that you can feed your plants regularly. Tea is usually preferred as it means you can regulate the amount of guano going into your soil.

How To Make Guano Tea:

  • Use around 3.5l water to 3tbsp guano.
  • Use around 3 parts warm water to 4 parts cold water to aid in dissolving the bat pellets. Do not use hot water!
  • Stir water as you add in the guano
  • Rest for 8-48 hours
  • After this, cover the mixture loosely and add air holes if necessary
  • Feed 3-4 times a week. You can alter the amount as you see fit, extra feeding may be required if you have good drainage in your soil.

Tip: You can reduce the amount of guano accordingly for younger plants if you feel it is needed. 1-2 tbsp should be enough.


A range of N-P-K ratios can be found in bat guano according to the diet of the bat. There is bat guano that is suitable for each stage of growth from seed to harvest.

Mexican Bat Guano:

  • Bug based diet - giving a high nitrogen ratio
  • Can be used from germination through to flower
  • Great for adding nutrients to the soil

Jamaican Bat Guano:

  • Fruit based diet - high concentration of phosphorous
  • Good for all stages of flowering, especially the early to middle stages

Indonesian Bat Guano:

  • High phosphorous content with the lowest nitrogen content
  • Cuts nitrogen levels in the soil making it great for getting the plant ready for the end of flowering period and final flush
  • Increases trichome levels

Organic gardening is often optimised through careful observation and trial and error. This article is a rough guide, not a precise discipline. Take careful consideration of your external factors influencing the plant growth such as the strain, light levels, pH and atmosphere when working with bat guano and in general.

Miguel Antonio Ordoñez
Miguel Antonio Ordoñez

Miguel Ordoñez is a long-time writer by trade. Utilizing his AB Mass Media and Communications degree, he has 13 years of experience and counting. He’s covered a wide array of topics, with passion lying in combat sports, mental health, and of course, cannabis.