Andre CampbellBat guano is a nutrient-rich organic fertilizer for plants.
It can help improve plant growth and may increase yields when used correctly. It is also suitable for lawns.
You can use it on many vegetables, nut trees, herbs, fruit trees, flowers, and ornamental plants.
Below are more benefits and uses of bat guano fertilizer.
What Is Bat Guano?
Bat guano is the accumulated excrement of bats. In simple terms, it is bat droppings that collect over time.
Commercial bat guano is usually sold as a dry powder, granule, or pellet. These products are made for use as organic fertilizers.
The word “guano” comes from the Quechua word wanu, which means dung or fertilizer [1]. The term generally refers to the accumulated droppings of bats and seabirds. People have used guano as a natural fertilizer for many generations.
Bat guano can accumulate in caves around the world. The deposits may also contain the remains of insects and other food eaten by bats.
Over time, layers of guano can build up and gradually break down. This creates nutrient-rich deposits that can be used as fertilizer.
Nutrients It Contains
Guano can be a rich source of nutrients for garden plants [2]. It supplies nitrogen, phosphorus, and potassium (NPK), as well as calcium, sulfur, and other trace nutrients.
- Nitrogen helps plants grow healthy leaves.
- Phosphorus supports root development, flowering, fruit production, and energy transfer within plants.
- Potassium helps plants grow strong stems and move water and nutrients through the plant. Healthy plants may also be better able to handle some stresses.
- Calcium helps build strong plant cells.
- Sulfur helps plants make proteins and chlorophyll. A sulfur deficiency may cause young leaves to become pale green or yellow. However, yellow leaves can have many causes, so a soil test may be needed to find the problem.
Guano content varies among species and across regional diets. It may also contain insect remains, including exoskeletons that provide chitin [3].
Chitin may support some beneficial soil microorganisms and may help stimulate natural plant defense responses. However, the effects can vary depending on the soil and growing conditions.
Because it can contain high levels of important plant nutrients, bat guano is often considered a nutrient-dense organic fertilizer for home gardens.
Bat Guano Benefits
Guano provides multiple benefits for the organic gardener.
The nutrients in bat guano can support healthy plant growth. Nitrogen helps leafy plants grow, while phosphorus and potassium support roots, flowers, fruits, and other important plant functions.
Some research suggests that certain guano products may affect some soil microorganisms. However, this does not mean bat guano is a reliable treatment for plant diseases. Use proper disease-prevention and management methods when needed.
Bat guano can also provide nutrients that help lawns grow healthy and green.
A further benefit for organic gardeners is composting. Small amounts of bat guano can add nitrogen to a compost pile. However, compost needs the right balance of materials, moisture, and air to break down properly.
When used according to label directions, some bat guano products can support the growth of seedlings and young plants.
Some bat guano products also release nutrients gradually. The speed depends on the product and soil conditions. Always follow the label directions.
Bat guano may also support soil microbial activity and contribute to soil fertility.
How to Use Bat Guano
Use guano carefully. Follow the package instructions to get the right amount and spread it evenly. If handled properly, it is safe to use both indoors and outdoors.
It is usually sold as a dry powder, granule, or pellet. Depending on the product, you can mix it into the soil or spread it around plants as a top dressing.
Some gardeners use bat guano tea as a foliar spray. However, evidence for using it to control plant diseases is limited.
For safety, apply homemade guano tea to the soil rather than spraying it on edible leaves. Only use a product as a foliar spray if the label specifically recommends this use.
Tea Recipe
To make a general bat guano tea, some gardening sources recommend mixing about 1 cup (236.5 ml) of bat guano with 1 gallon (3.78 L) of chlorine-free water.
Always check the product label first because bat guano products vary in strength.
Let the mixture sit overnight, then strain it before applying it to the soil around plants.
How Much Bat Guano Tea Should You Use?
There is no single amount of bat guano tea that works for every plant. The right amount depends on the plant’s size and the strength of the tea.
For small seedlings, you could start with about 100–250 ml (⅓–1 cup) around the soil. Larger plants may need more.
If the product label gives a different dilution or application rate, follow the label instead.
Avoid soaking the soil with too much fertilizer tea.
Plants That Benefit from Bat Guano
Many vegetables, flowers, herbs, shrubs, fruit trees, and ornamental plants can benefit from properly applied bat guano fertilizer.
Bat guano fertilizer can also provide nutrients for vines. When used correctly, bat guano can help lawns grow healthy and green.
NPK Ratio
Bat guano’s NPK ratio varies depending on the bat species, diet, and processing.
Bat guano fertilizers are often higher in either nitrogen or phosphorus. For example, some products may have an NPK ratio of 10-3-1, while others may be closer to 3-10-1.
Products with more nitrogen are often used to support leafy growth.
Some gardeners use products with higher phosphorus levels for plants with specific phosphorus needs. However, adding extra phosphorus does not always improve flowering or fruiting.
A soil test can help show what nutrients your soil needs.
Always check the product label for the specific NPK analysis before applying bat guano to your plants. Actual NPK values vary widely among commercial products.
Where to Find It
For home gardeners, the safest option is usually a packaged product sold for gardening use. Choose a product with clear directions and an NPK analysis on the label.
Natural bat guano deposits can be found in caves in many parts of the world. However, collecting guano yourself can be dangerous and may be restricted in some areas [4].
Caution
Do not breathe in dust from dry bat guano. Wear gloves and follow the safety instructions on the package.
A suitable mask or respirator may also be needed when handling dusty products.
Raw or dried bat guano may contain microorganisms and fungal spores.
Some bat guano may contain Histoplasma, a fungus that can grow in soil or other material contaminated with bird or bat droppings. Breathing in spores from this fungus can cause a lung infection called histoplasmosis [5].
This is one reason to avoid disturbing large amounts of bat guano or breathing in its dust.
Takeaway
People have used guano as fertilizer for many generations.
In some regions, authorities regulate the harvesting of bat guano to help protect bat populations and cave ecosystems.
When used correctly, bat guano can be a useful organic fertilizer for many gardens. Always follow the product label and handle it safely.
Sasha Campbell
Can I ask the dosage of applying tea per plant. I mean how many ml per plant?
There is no single amount of bat guano tea that works for every plant. The right amount depends on the plant’s size and the strength of the tea.
For small seedlings, start with about 100–250 ml (⅓–1 cup) around the soil. Larger plants may need more.