bat guano for weed plants

Bat Guano: The Cannabis Superfood Rich In Macro And Micronutrients

Guano has a long history as a high-performance organic fertiliser. When you see the benefits of guano on cannabis plants, you will immediately comprehend why wars have been fought and fortunes have been made and lost because of guano.



Bats are very social creatures. These adorable little mammals form large colonies that share the same cave for generation after generation. Over the centuries, dunes of excrement build up on the floor of the roost cave, becoming compost. What results is guano, called “wanu” by the ancient South American Quechuans.

Guano is a plant superfood that is rich in the three essential plant nutrients, nitrogen, phosphorus, and potassium. Nitrogen ensures vigorous and verdant growth during the vegetative cycle. Phosphorus supports healthy flowering and root growth. Potassium ensures sturdy trunks and branches. Guano also contains a complete range of micronutrients for overall healthy plant development.

The diet of the particular bat species can alter the nutrient profile of the guano. Insect-eating bats produce a guano that has a high nitrogen content. This makes it ideal for fertilising during the vegetative phase. Fruit-eating bats produce a guano that has a high phosphorus content. This is best for use during the flowering phase when cannabis has a higher demand for phosphorus.

Guano is ideal as an organic soil amendment, either dug-in around the plant or watered-in as a tea. It makes an ideal backbone to any soil recipe, and has the unique characteristic of never burning plants, unlike most nutrients. Fruits and vegetables grown with guano are more flavoursome and resistant to disease. It is the same with cannabis. Guano will “mango” or sweeten the bouquet and flavour of buds when dry.



Use guano as part of an organic soil mix from the start. Along with bone meal, chicken manure, feather meal, and rock dust, guano provides a broad spectrum of essential nutrients, vitamins, and minerals for the cannabis plant. Try this recipe for bountiful cannabis growth.


Probably the most convenient way of adding guano to your garden. Here’s a recipe:

  1. Use 1 tablespoon of guano per litre of water
  2. Use warm water, not hot! You will kill the microorganisms
  3. Stir the water as you add the guano
  4. Leave to rest overnight
  5. Use once per week to guarantee lush growth

Add guano to the soil for a boost in plant performance. Here’s how:

  1. Dig it in (under the mulch) so that it activates properly
  2. It will dry, clump, and not work as effectively if only sprinkled on the surface
  3. Water-in well


The savvy contemporary cannabis consumer is learning to demand high-quality, organic marijuana. Guano is one way of achieving world-class quality when growing organically indoors or outdoors.

The benefits of guano for plant growth are numerous:

  • It improves soil texture. If the soil is too loose, guano will bind it better and increase water retention. If the soil is too dense, guano will loosen the texture and let water penetrate more efficiently.
  • Bioremediation. Guano can help flush toxic elements from the soil while protecting the roots microbially and continuing to feed the affected plant.
  • It encourages healthy decomposition of exhausted material. Adding guano to compost speeds up the composting process and improves friability.
  • It is a slow-release fertiliser. Guano will provide nutrients for most of the life of your plant.
  • It is a pH-adjuster, buffering the pH of the root system.
  • It controls nematodes and is a natural fungicide against chitin (from insect shells).
  • It keeps soil friable and acts as a soil conditioner. Guano adds beneficial enzymes and microflora for continuous soil health.
  • When combined with other additives like worm castings and various meals, guano helps create thriving colonies of root fauna.
  • Used as a dilute spray, guano can help provide plants with fungal protection.


Guano has a long and interesting history as one of the most prized fertilisers in the world. Since well before the arrival of Europeans, guano was a revered fertiliser by the Incas and older South American cultures. It was so important that Incan rulers divided the guano-bearing islands among the provinces. How much could be mined and when were strictly regulated.

Between 1806 and 1841, guano caused astonishment and trepidation in European and new-American farmers. This horticultural curiosity caused such huge and healthy plant growth that it was feared the soil may be depleted irreparably. Within a few years though, it was in great demand by every farmer in the world.

Two million tonnes were imported by Britain from 1840 onwards, and the government of the United States made it a matter of agricultural necessity. During his tenure, President Fillmore said “Guano has become so desirable an article to agricultural interests in the US that it is the duty of the Government to employ all means properly in its power for the purpose of causing this article to be imported into the country at a reasonable price”.

Massive fortunes have been won and lost over the centuries from guano mines. In the mid to late-nineteenth century, it caused a mania not unlike the California gold rush. Over a forty-year period, Peru exported over twenty million tonnes of guano around the world for a profit of two billion dollars.

Rich in essential macro and micronutrients, bat guano is an organic superfood that will delight the contemporary cannabis grower. For naturally flourishing plants, guano is an unbeatable addition to any organic grow, both indoors or outdoors.

Guano has been a respected organic fertiliser for centuries. When used to grow cannabis, it often produces spectacular results.

Feeding Your Weed The Natural Way: Using Bat Guano To Grow Cannabis

Yes, you can go to your local hydroponics store and spend good money on dozens of bottled chemical fertilizers designed to bulk up your bud. But none of them work as well as an all-natural, organic product made by furry, flying mammals right across the world. We are, of course, talking about bat guano.

What’s So Special About Bat Guano?

Bat guano fertilizer is harvested from the decomposed droppings of bats. Yes, you read that right – the best organic fertilizer in the world starts as bat poop. Specifically, from cave-dwelling bats found primarily in Mexico, Jamaica and Indonesia.

Because these bats live in the same cave for generations, their excrement builds up on the cave floor and the organic matter quickly decomposes, leaving behind an amazingly rich blend of all the nutrients contained in the bats’ diet.

High Yielding Strains

Bat Guano And Cannabis: A Perfect Match For Plant Health

Although primarily used as a macronutrient fertilizer, using bat guano for cannabis is also great, as it contains suitable micronutrients that become readily available as they decay into the soil. Because bat guano is teeming with microbial life, it’s a great regulator of soil microfauna. This means bat guano in soil helps to make the nutrients more available, while also acting as an organic fungicide as the beneficial microbes attack the harmful fungus.

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Does The Source Of Bat Guano Matter?

Bat guano is made from whatever the bats are eating. Because of this, growers can tailor the specific bat guano fertilizer they give their plants during each stage of growth depending on the source of the nutritional additive.

Bat Guano From Mexico

Mexican bat guano is predominantly harvested from insectivorous (insect-eating) bats, such as the Mexican free-tailed bat. Thanks to their bug and insect-filled diet, Mexican bat guano has a high nitrogen content. This makes it perfect for fertilizing your cannabis during the vegetative stage of growth, as nitrogen is an essential nutrient for the plant’s ability to photosynthesize.

Indoor Cannabis Strains

Bat Guano From Jamaica

Jamaican bats, on the other hand, eat fruits and berries as well as insects. This is equally great for cannabis growers, as fruit and berries are one of the best natural sources of phosphorus, which helps cannabis plants during flower formation. All you need to do is wait until the first few weeks of flowering to feed your plant some Jamaican bat guano.

Bat Guano From Indonesia

Another place bat guano is commercially harvested is on the islands of Indonesia, where the bats are frugivores, meaning their diet consists solely of fruit and berries. Because these Indonesian bats are such picky eaters, the guano they produce has the highest ratio of phosphorus to nitrogen. With such a high ratio, using Indonesian bat guano for flowering is ideal, as the phosphorus helps plants with flower formation without any nitrogen, which would cause the production of unwanted foliage.

How To Feed Bat Guano To Cannabis

Some of the easiest methods of using bat guano for weed are pre-mixing into the soil, hand watering once planted, and direct soil application. Let’s quickly take a look at what steps need to be taken for each method.

Mixing Into Soil

Whether you’re using pots or planting directly into the ground, your cannabis plant will benefit from the slow release of organic nutrients provided by the addition of guano to the soil. To apply it, simply add two heaped tablespoons per 7 liters (1.8 gallons) of soil substrate and mix thoroughly. If time allows, it’s best to let this soil mix sit, covered, for up to a month so that the microfauna has a chance to make the nutrients available from day one.

Feeding As A Tea

Making a bat guano tea recipe for flowering or vegging is very simple – all you need to do is add 3 tablespoons of bat guano to 3.5 liters (1 gallon) of warm water and mix thoroughly. Once the guano is dissolved, let the tea sit overnight and feed your plants with it the next day.

Burying Bat Guano

An even simpler method of feeding bat guano to your cannabis is direct soil application, or burying it. To do this, the best way is to dig a shallow (5cm) ring around the trunk of your cannabis plant, halfway between the trunk and the pot walls. Next, scatter two heaped tablespoons of guano per plant, then cover it with soil and, if you’re using it, mulch.

Pre-Mixed Potting Soil: As Easy As It Gets

Luckily for us, there’s also another convenient way to get bat guano into your cannabis garden without even getting your hands dirty, and that’s with pre-mixed potting soil containing bat guano! Using this is the most straightforward way of ensuring your cannabis plant has access to the benefits of bat guano nutrients.

Happy Frog

Happy Frog organic potting soil by Foxfarm is a perfect medium in which to grow cannabis, as it’s made with a premium, organic soil base that’s amended with earthworm castings and, most importantly, bat guano!

Ocean Forest

Another product from the Foxfarm line, Ocean Forest is an all-in-all potting soil for cannabis. Made with the same organic base as Happy Frog, Ocean Forest soil then has sea-going fish and crab meal mixed in, creating a cannabis potting soil that can be used straight out of the bag.

Go All Natural – Use Bat Guano

The continued success of bat guano for both home and commercial cannabis cultivation demonstrates how growers can utilize the power of naturally-produced and completely organic fertilizers to grow some of the best weed in the world. And you can, too! Use bat guano, and never again risk overfertilizing your cannabis or having any of the dangerous residue from chemical fertilizers in your final product.

The continued success of bat guano for cannabis cultivation demonstrates how growers can utilize the power of completely organic fertilizers to grow some of the best weed in the world