Would nations go to war over who gets to keep your poo? If you’re a bat, then yes, they would. (If you’re not poo-thievery-worthy, you’re in the majority though, so don’t take it personally.) Bat excrement is among the three animal dookies given the lofty title “guano,” the Hispanicized form of “wanu,” the Quechua word for “fertilizer.” (Birds and seals are the other two “guano” honorees, in case you were wondering.) Like cannabis, bat guano has an astonishing number of uses, and one of those uses is to help weed grow during its vegetative and flowering stages. Why bat poo in particular? Surprisingly, there’s a very precise alignment of weed’s needs and bat guano’s resources; pot needs their poo.

Poo Worth Fighting For

Bat guano is such a potent fertilizer, while also containing a key gunpowder ingredient, that it has attracted bellicose competition. A naval conflict broke out in 1864 between Spain and Peru over the Chincha Islands, which, according to Smithsonian Magazine, were covered in mounds of guano over 100 feet tall. As reported by the Breakthrough Institute, the islands were so crucial that the war over them roped in Chile, Bolivia and Ecuador too. Fifteen years later, another guano war – the War of the Pacific – broke out between Bolivia, Chile and Peru.

Islands containing copious amounts of bat guano sparked naval wars for access to that precious natural resource. Image in Public Domain 

Islands containing copious amounts of bat guano sparked naval wars for access to that precious natural resource. Image in Public Domain

When the American Civil War broke out in 1861, bat poo was equally crucial. Although it wasn’t central to the armed conflict, it was still indispensable to it. The Confederate Army had to locally source gunpowder components due to supply shortages and a Union blockade on Confederate ports. Bat caves in Virginia provided the guano, which contained the gunpowder component saltpeter, and other resources in that state provided the other gunpowder ingredients. Thus, the guano enabled the fight to go on – to no one’s betterment, granted.

A simple online search with the key words “guano” and “war” turns up additional results, making it clear that people were willing to go to great lengths to be fully stocked on bat poo.

Why Bat Guano in Particular Is Weed’s Best Friend

Bat guano contains all the macronutrients and micronutrients that healthy, thriving cannabis plants need, including boron, calcium, iron, manganese, sulfur, zinc and magnesium. Of greatest importance, bat guano contains nitrogen, which ensures growth during the plant’s vegetative cycle; phosphorus, which supports healthy flowering and root growth; and potassium, which ensures sturdy trunks and branches. (For a more thorough explanation, read this Premium Cultivars article.) All of those things enhance the health of cannabis plants, but they also sweeten the flavor of the plants’ dried buds. Administering bat guano during the flowering cycle allows the terpenes and final flavor to become bold and long-lasting.

Beyond that though, guano is just good for plant growth overall. It binds or loosens soil as needed to maximize water absorption, cleans the soil by removing toxic elements from it, attacks fungus, and conditions soil with health-boosting enzymes and beneficial microbes.

When the cannabis plant is flowering, feeding it bat guano makes the final flavor sweeter and longer-lasting. Photo By The Original Creators Of Apache Flink® Ververica via Creative Commons

When the cannabis plant is flowering, feeding it bat guano makes the final flavor sweeter and longer-lasting. Photo By The Original Creators Of Apache Flink® Ververica via Creative Commons

So, how do you feed your cannabis plant this seemingly custom-made magical dung? Usually, bat guano comes packaged in the form of pellets or powder. Some growers who purchase the powder dissolve it in chlorine-free water before infusing it into the soil either before planting or during growth. This method allows the plant roots to seep the nutrients deeply as the guano becomes a slow-release fertilizer with high nitrogen content. Alternatively, the powder can be incorporated into aerated compost extracts before being applied to the soil. (For illustrated step-by-step instructions for feeding bat guano to cannabis, read this Herbies Head Shop article.) A word of caution though: Wait to introduce the guano until after your cannabis plants have passed their seedling phase. Otherwise, the nutrients can burn the plants.

Three Things to Remember When Buying and Using Bat Guano

1. Only buy bat guano from ethical companies that operate in sustainable areas. Sourcing bat guano, which is typically only adequately supplied by bat caves in Mexico, Spain, Thailand, Indonesia, Jamaica, Peru, India and other parts of Asia, can be expensive and difficult. (The largest bat colony in the world and the largest in North America are both in Texas, but they’re full of Mexican bats.) Some companies resort to unethical harvesting methods that harm bat populations and their ecosystems. The International Union for Conservation of Nature (IUCN) provides detailed protocols for sustainable guano harvesting. For now, those are optional rules, but IUCN hopes to make them enforced internationally at some point.

2. Do not inhale powdered bat guano. Whether you breathe it in incidentally while mixing fertilizer with water, or you deliberately huff feces, you’re susceptible to contracting the fungus-induced disease histoplasmosis. (“DON’T SNORT POO” is a stand-alone best practice in life though, too.) Always wear a face mask while mixing bat guano fertilizer.

3. Make sure the guano comes from insect- or fruit-eating bats, not blood-drinking bats. Guano from insect-eating bats contains more nitrogen, rendering fertilizer derived from it ideal for your plant’s vegetative phase. Guano from fruit-eating bats has more phosphorus, which makes its fertilizer best for the plant’s flowering phase. Guano from blood-drinking bats – which nearly always sip from the veins of cattle and horses, not humans – doesn’t provide the nutrients that cannabis craves; basically you’d just be taking a proxy dump on your beloved plant. Don’t trouble yourself with scrutinizing labels though. Those bats make up only three of the more than 1,400 bat species, and manufacturers in the bat guano business aren’t likely to mistakenly harvest the wrong poo.

The majority of bats consume insects or fruit, with each diet contributing to specific nutrient-rich portions of the resultant guano. Photo by Eve Rox Photography via Creative Commons

The majority of bats consume insects or fruit, with each diet contributing to specific nutrient-rich portions of the resultant guano. Photo by Eve Rox Photography via Creative Commons

Get Guano and Give Back!

If you’re growing your own ganja garden, bat guano could be what you need to get the most out of your plants. Poo is one of nature’s freebies, so avail yourself of one of the many gifts that bats give us. And if you’re able to, help out our mammal buddies as well by supporting Bat Conservation International, building a bat house in your backyard, following the National Park Service’s do’s and don’ts, or taking ideas from the U.S. Fish & Wildlife Service. Also, check out the things going on each year during internationally celebrated Bat Week (Oct. 24-31). You’ll discover that there’s a lot more than feces to appreciate about these little critters – but now you know just how awesome their feces are too!

Kathleen Hearons is a writer, editor, linguist and voice over actor from Los Angeles. She specializes in creative writing and research-intensive analysis and reporting.  




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