Bananas are a healthy and tasty snack. They contain several bioactive antioxidant compounds like phenolics and carotenoids that are good to include in our diet. And don’t get me started with the banana peels.
Did you know that banana peels are considered to be useful for plants in the garden?
Most of us consider banana peels as a waste product. It makes up about 25-35% of the fruit by mass. If you don’t have a compost system, most banana skins end up in landfills along with other food waste.
In this article, we offer some tips on how to turn this kitchen waste into your new gardening staple.
In This Article
Are banana peels good for plants?
Fertilizers are organic or inorganic material added to the soil to supply one or more nutrients that plants need to grow. Natural and organic fertilizers like banana peels are often better instead of synthetic ones for several reasons.
First, organic matter improves the soil’s ability to hold onto water and nutrients. Chemical or synthetic fertilizers get a lot of water from the soil, contaminating it and brings about pollution in the water.
Another advantage is that carbon helps microbes thrive. These microbes are responsible for the natural biological processes necessary to break down matter.
Lastly, they are more sustainable and environmentally friendly as they help reduce food waste and they do not decrease runoff water quality.
Natural fertilizers like coffee grounds and eggshells have often been subjects of curiosity as good homemade fertilizer options. Among these, banana peels are also noted as a good source of nutrients for plants.
N-P-K content of banana peels
Banana peels contain 42% potassium (K) and 3% phosphorus (P) in ash form according to The Nutrient Company. These elements are two of the three most important components (along with nitrogen) of fertilizers often referred to as the N-P-K ratio. Plants take up large quantities of these essential nutrients in their life cycle. Potassium also plays an important role in nitrogen metabolism.
Potassium in banana peels
The highest organic sources of potassium are banana peels. It helps plants create flowers, produce fruit, and promote the healthy growth of roots. Including potassium in optimum amounts in fertilizers also helps the plants to efficiently transfer other essential nutrients and water between plant cells, and regulates enzyme activity involving carbon and nitrogen metabolism in the plant.
Think of potassium as the plant’s supervisor, assisting chemical and metabolical processes to sustain life. It also helps them fight off diseases, survive in a drought, and improve general plant health.
Other helpful nutrients
Apart from potassium, bananas have good concentrations of calcium (Ca), manganese (Mn), magnesium (Mg), sodium (Na), and sulfur (S), nutrients that support overall plant vigor.
Calcium prevents blossom end rot in fruits of plants like tomatoes.
Manganese helps support healthy photosynthesis.
Sodium helps water flow between cells similar to potassium, and;
Magnesium and sulfur boost chlorophyll production.
Banana peels especially benefit flower and fruit-bearing plants because they contain minimal nitrogen. The abundance of nitrogen would create a lot of green leaves but few fruits. But even nitrogen-loving plants like beets and Brussels sprouts will benefit from banana peel fertilizers.
How do you know if your plants need more potassium?
Potassium (K) is naturally present in soils in varying amounts. But only a relatively small amount is readily available for plants to use.
Several factors affect K availability in soils like:
the original content of K in the soil parent material (depending on what type of soil and primary minerals are available in the area)
different weathering degrees (rock material needs to break down or weather to become soil)
availability of other sources like K ions dissolved in water
A K boost might be needed if you see the following symptoms:
Yellowing leaves on the bottom of the plant
Older leaves have brown veins or spots
Plant growth may slow down or completely stop
It is better to get your soil tested to know for sure if your soil needs a potassium boost just to make sure. Submit samples to a soil lab or purchase a testing kit at your local garden center.
Three ways to make banana peel fertilizers:
If you are sure that your garden needs more potassium, here are three ways that use the banana peels as fertilizer in the garden (modified from the Project Diaries on YouTube).
Easy 1-step natural banana fertilizer
Bury the banana peels in the garden in three-inch deep holes around the base of the plant (relatively near the roots) and allow them to decompose to release the nutrients slowly.
This is a great way to prepare garden soil before the planting season. This is especially helpful for germinating seeds. The banana peel makes a wonderful nutrient-rich side-dressing for plants to help boost plant health. It would be more manageable to add chopped banana peels to the soil.
Make sure to bury the peels relatively deep so that the peels in the garden won’t attract unwanted animals or insects.
Brewed banana peel tea
Fill a glass jar or any container with water and soak as many bananas in. If you have time, chop up the banana peels to help them release more banana goodness and compact them into the jar further.
Make sure to completely cover with water or else it might get moldy and become useless.
Keep the brew out of direct sunlight for a week or two.
Check if the banana peel tea is completely submerged every so often because the water may evaporate.
Create the nutrient-rich liquid fertilizer by diluting 1 part banana peel tea to 5 parts water ratio.
You can compost the soaked banana peels or simply bury them in the soil, and your plants will love you for it.
Once a week, water your plants using the diluted banana peel liquid fertilizer at the base. The liquid fertilizer gets absorbed by the roots immediately. Or spray directly on the plants for some quick pick me up.
This requires a bit more effort and time. But it would be worth it when you see your plants grow stronger and healthier week by week.
Be patient. It will take some time to see the results. Use the fertilizer every week continuously to see the best results.
Increase soil acidity
Leaving the banana skin soaked in water to ferment for a month will turn it into vinegar. Acidic soil-loving plants like rhododendrons, hydrangeas, and gardenias will especially love this special treatment.
Banana peel powder for the soil
Finely powdered fertilizers are slow-releasing organic fertilizers. These types quickly dissolve and become available to boost plant vigor. It’s like giving your plants some supplements for trace elements and nutrients not present in your garden.
To make the banana peel powder fertilizer:
Completely dry banana peels in the sun or oven-dry at a low-heat setting until it turns black and brittle.
Grind the dried banana peels using mortar and pestle or an electric blender to a fine powder product.
Add the dried banana powder straight to the soil.
Store in a dry place.
It is best to add the banana peel powder a few months (around 3-6 months) in the garden soil before using it. Again, this may be time-consuming but is easy to make.
Results of a study of nano-fertilizer extracted from banana peels applied to tomatoes and fenugreek showed that germination percentage improved with increasing dose of banana peel extract for both plants.
For tomatoes, the germination percentage increased from 14% (without nano-fertilizer) to 97% after 7 days of planting. The same trend was observed for fenugreek from 25% to 93% germination percentage.
The nano-fertilizer was made from shredded and blended Egyptian banana. The slurry was mixed with potassium hydroxide and vacuum filtered to get a clear brown substance. This was dried and ground to powder to use as a nano-fertilizer.
If you don’t want to go through the hassle of buying a banana peel nano-fertilizer, you can settle for a simple banana peel. To do this, place the seeds directly on top of a banana peel before you plant them in the soil.
Although it’s probably not as effective as the nano-fertilizer, the decomposed banana peels still offer rich stores of healthy nutrients to the soil like iron, calcium, potassium, and phosphorus.
Why not give them a headstart in life, right?
Is one method recommended over another?
There are not a lot of scientific studies to say if one type or method is better than the other. However, most studies use fruit peel fertilizers in the form of powder.
Organic fertilizers in powder form prove to be potent in giving effective nutrients for improved plant development, higher yield in crops, and increased growth in microorganisms.
Can you use it in potted or plants in a container?
You can use banana peel fertilizers in plants on a container. Being contained will help keep the nutrients in and prevent them from washing away easily.
Simply bury the chopped banana peels on the soil in the pot or water the plant with the liquid fertilizer as usual.
What about air plants you say?
Since air plants do not need soil to thrive, a generous spray of the diluted banana peel tea can benefit them. Alternatively, arrange a banana peel at the air plant’s base and cover it with some mulch. The peels would act as compost base and will release healthy nutrients as they decompose that will benefit the plant.
Composting banana peels
Some would argue that the peels aren’t at all that special for the garden and are better dealt with in the compost. The banana peels won’t easily decompose under the soil because it needs the oxidative power of the air to break down the organic matter.
Since banana peels are not complete fertilizers, it could be better to feed your plants with a more complete supplement by preparing proper gardening compost. But composting is not an easy do-it-yourself project.
If done right, the peels in the compost pile will help add all the wonderful elements (all the N-P-K it needs) as it gets blended with nitrogen-rich materials necessary for the holistic development of plants. The organic material in the peels would help the compost retain more water as it blends with other organic materials.
Help hasten the process of decomposition by introducing chopped peels to the compost instead of the whole banana peels. The smaller, the better.
Yes, you can make tea from compost. But it’s for your plants, of course! It is a nutrient-packed drink for plants. The microbes in the compost help turn this nutrient-rich organic matter into plant food. Here’s a recipe:
Add 1-2 cups of compost mixture into 5 gallons of water. It is better to use rainwater or leave tap water to sit for over 24 hours. Add some food source for the bacteria or fungi like molasses or ground-up fish.
Allow the mixture to brew for 24 to 36 hours. Any more than that might not be helpful.
Et voila! That’s your homemade brew of compost tea.
It is recommended to dilute it to at least a ratio of 1 part tea to 4 parts water. You may apply it directly to the soil with a watering can or use it as a foliar spray.
Foliar feeding helps boost the health of plants that have diseases or infestation. Do this by directly applying the liquid fertilizer to the leaves. Those experienced in the garden recommend applying the treatment at least bi-weekly.
Results won’t be immediate but there will be a difference.
Can too much potassium kill plants?
Using organic material as fertilizers usually doesn’t lead to an oversupply of nutrition. But too much of a good thing may also be a cause for concern.
There are a few things to consider like the original K content of the soil. These elements come from the breakdown of minerals like feldspars like those of orthoclase and micas.
Other sources of K in the garden soil may be in solution as ions in water or from other decaying material containing carbon.
Too much potassium could affect the way the soil absorbs other critical elements. If this is the case, here are some nutrient deficiency symptoms to look out for:
A lack of nitrogen can stunt plant growth and lead to a yellowing of older leaves. There will be a decrease in the production of chloroplast and chlorophyll. These compounds give leaves their lovely green color. There will also be a noticeable red tint in the veins of the leaves. New leaves will be significantly smaller in size or be inhibited from growing.
To help improve these symptoms, primarily using nitrogen-based fertilizer can help.
Magnesium and Manganese Deficiency
This can be observed as yellowing from the veins to the leaves of the youngest leaves. In some tomatoes, the advanced stage of magnesium deficiency leads to purpling of the affected areas of the leaves. Sometimes tan sunken spots would appear in the leaves. Gray and black spots which are dead plant tissues also begin to show.
Watering with Epsom salt (magnesium sulfate) can help with magnesium deficiency. Introducing other fertilizers in the mix like manganese sulfate or manganous oxide could also be helpful.
Again, it is best to do a proper test by submitting samples to a laboratory or using testing kits available in the market.
Banana Peels as a Natural Alternative
Here are other ways to use banana peels as an eco-friendly alternative to commercially available products.
Banana peel as a natural pest repellent
The chopped-up banana peel in the soil also helps control pests like aphids. Bury the peels around the base of the plant to keep pests away.
Another way is to spray the mix of banana peel tea and water directly onto plant leaves surfaces and stems to serve as a natural pest repellent.
The pulp and banana skins of fully ripe bananas also have antifungal and antibiotic properties. The fungicide in the peel and pulp can be used to treat fungal disease in tomatoes.
Chop up banana peels and place them in a mason jar or plastic container. Punch holes in the cover big enough to fit the size of fruit flies or other unwanted insects. Mix apple cider vinegar and fill to the level of the banana peel.
The scent of the apple cider vinegar and banana peel attracts the insects. Your homemade trap is complete!
Instead of repelling pests, why not attract pollinators. Use banana peels to attract butterflies and other animals like birds and bees. Make sure to place them in a high enough place so that ants can’t get to them.
Other helpful tips:
If you have too many bananas, don’t get rid of them. You can keep them in the freezer, and once you have time, defrost and use the banana peels in the garden.
If you also have seaweed or kelp available, add water and take the diluted solution. Spray this to the banana peels to feed the microbes. They will help break down the bananas quicker.
Use banana peels with other kitchen scraps turned fertilizer like coffee grounds and eggshells.
Overall, using banana peels as an organic fertilizer in the garden is a good idea. Technically, all organic matter is beneficial for soil and plants. If you prefer to subscribe to natural fertilizers and keep to a budget, maybe using banana peel is worth considering.
The deciding factor would be the amount of time and effort you are willing to spend on the fertilizers. And of course, it depends on how many bananas you have available. So, make sure to feed yourself some banana goodness too!
There is no secret one-fits-all formula. It is always better to give your plants a completely balanced package. Try composting your banana peels properly to get the most benefit. Composting ensures that your plants get all the necessary amounts of nitrogen, phosphorus, and potassium it needs to thrive.
Take these tips with a grain of salt and test them out for yourself. There will only be two results. Either it helps, or it won’t. Experiment! Try testing it out on one plant with a control plant and see which thrives! Who knows, maybe this will be your go-to method from now on.
If you use banana peels in your garden, you will not only help lessen food waste but might also improve the state of your garden. Your plants just might go bananas.