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 upon 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 guano that has a high nitrogen content. This makes it ideal for fertilizing during the vegetative phase. Fruit-eating bats produce guano that has a high phosphorus content. This is best for use during the flowering phase when plumeria 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 flavorsome and resistant to disease. It is the same with plumeria. Guano will “mango” or sweeten the bouquet and flavor of buds when dry.



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


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

  1. Use 1 tablespoon of guano per liter 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 plumeria 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
Bat Guano Organic Soil Mix


The savvy contemporary plumeria grower is learning to use high-quality organic fertilizers.

The benefits of guano for plumeria 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 the healthy decomposition of exhausted material. Adding guano to compost speeds up the composting process and improves friability.
  • It is a slow-release fertilizer. 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 fertilizers in the world. Since well before the arrival of Europeans, guano was a revered fertilizer 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 plumeria grower. For naturally flourishing plants, guano is an unbeatable addition to any organic growth, both indoors or outdoors.

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