Homemade Dry Banana Peels as a Fertilizer

Every gardener knows that your plants, whatever you’re growing, need lots of water and attention from you, and also protection from pests if they are going to thrive. But that isn’t all they need…

Plants also need food, and that means fertilizer. Fertilizer supplies the needed elemental nutrients that all plants must have in order to grow and stay healthy.

Sure, you can buy over-the-counter fertilizers, but they can be expensive and, in some cases, tricky to use. You can go old-fashioned and make compost from kitchen scraps, but that takes a lot of time.

A better bet, I think, is to make simple fertilizer directly from those same kitchen scraps. The best scraps for the purpose, if your plants need potassium, are banana peels.

With just a little bit of processing time, you can quickly turn dried banana peels into easy-to-use fertilizer. I’ll tell you everything, step by step, in this article.

Are Banana Peels Good for Plants?

Yes, they really are! Banana peels, just like bananas themselves in our own diet, are a great source of potassium.

Potassium is an essential, elemental nutrient that all plants need, one that helps them develop strong, properly formed root networks, retain water, and also produce healthy flowers and fruit.

Even though all plants need differing amounts of it, they all need at least some, and that makes banana peels a great resource for taking care of your garden. Potassium is especially important for heavy feeders and helping plants recover from drought and other stress.

No matter what you’re growing, if your plants aren’t getting enough potassium, they will have weak root systems that are vulnerable to disease, and those stunted roots will invariably result in slow growth and poor performance overall.

Using nothing more than these peels and a little bit of time, you can keep that from happening!

Supplies and Equipment

You don’t need much to make your banana peel fertilizer. Chances are pretty good you’ve got all this stuff in your kitchen right this moment.

Banana Peels: If you want to make banana peel fertilizer, you’ve got to have lots of banana peels! How many you’ll need depends on how much fertilizer you require.

The rule of thumb is that one intact banana peel will yield about one level tablespoon of fertilizer powder once it is dried and processed.

You’ll need bunches of bananas to make enough to do a sizable garden or raised beds. That means you’ll need to collect the peels for a time and to do that you’ll need…

Freezer Bags: You don’t have to waste edible bananas or keep rotting, make tiny batches at once, or keep slimy peels lying around until you have the right quantity.

Anytime you peel a banana, simply pop it into a gallon-sized freezer bag and put it in the freezer. This will prevent mess and odor until you are ready to process.

Knife: Any kind of sharp knife will do the trick when it’s time to start trimming the peels and cutting them down to size.

Cutting Board: Likewise, any cutting board works just fine for this work, plastic, or anything else.

Blender or Food Processor: Once you have properly dried out the banana peels, it’s easy to turn them into powder and thus make them ready to use with a blender or food processor.

If possible, make sure your unit can accept a fine grinding blade, as that will produce better results.

Oven: Any common oven will do the trick for drying out your banana peels quickly and efficiently. If you have one, a food dehydrator also works well, but it isn’t strictly necessary.

Baking Sheet: Needed to hold your banana peels while they are drying in the oven.

Glass Container: For storing your finished banana peel fertilizer powder.

Eggshells, Crushed (if desired): Your ground banana peels can be used as an ingredient in a liquid fertilizer spray by adding a couple of additional components. One of them is calcium carbonate, easily harvested in the form of eggshells from your kitchen.

You don’t have to go to this trouble if you don’t want to, because your peel powder will still give plants lots of potassium by itself and a few other trace nutrients.

Epsom Salt (if desired): As with the eggshells above, if you plan on using your banana peel powder as part of a fertilizer spray, Epsom salt is a great additive because it will add much-needed magnesium. Again, not necessary if you are applying it directly dry.

And that is all you need! Now, let’s learn how to make your fertilizer powder.

Here’s How to Make Your Dry Banana Peel Fertilizer

The steps below will guide you step by step through making your potassium fertilizer powder from dried banana peels. It’s really easy, but as always, I strongly recommend that you read over all the instructions before you begin.

Step 1: Gather banana peels. You’ll get a much better yield and save effort and energy in the long run by accumulating a sizable bag of banana peels before you begin.

Remember to put them in a freezer bag and keep them in your freezer to prevent them from rotting and getting nasty until you need them.

Once you have enough peels (20 to 30 for the average garden, if you want to fertilize all of it), it’s time to start processing!

Step 2: Let the peels thaw. Once you’re ready to begin, take the banana peels out of the freezer, remove them from the bag, and lay them out on a cutting board or other clean surface to fully thaw.

Depending on the temperature in your home and the quantity of the peels, this will take anywhere from 30 to 45 minutes.

Step 3: Prep peels. Using your knife and cutting board, cut off the stems and the little wooden cap or bud from the ends of each peel. Discard these pieces.

Step 4: Cut peels down to size. Continuing on with the knife and cutting board, separate each section of each peel, then cut those sections down into one-by-four-inch strips.

They don’t have to be perfectly consistent, but they should be close to ensure even and speedy drying in the oven. Smaller pieces also make later processing easier.

Step 5: Place pieces on baking sheet, preheat oven. Turn your oven on and set the temperature as low as it will go.

The ideal temperature is 150° F / 65° C. It’s okay if it won’t go that low, but if your oven won’t go below 300° F / 150° C, you’ll need to keep the door cracked to let some of the heat out.

Place the banana peel pieces on the baking sheet in a single layer. Don’t pile them up, but you can place them on the sheet in tight rows because they will shrink as they dry.

If you are using a food dehydrator, set the temperature to 150° F…

Step 6: Place tray in oven and set timer. Load the tray into the oven, remembering to keep the door cracked if your minimum temperature is 300° F or above. Set your timer based on your temperature setting: your peels will take around 6 hours at 150° F, and 4 hours at 300° F.

Step 7: Check on the peels for dryness. Every hour or so, take a peek at the peels to see how they’re coming along.

As they dry out, they will turn dark brown, shrink, and start curling at the edges. Once they are very dark brown and uniform, they are probably done.

Step 8: Test. Don’t assume your peels are done just because they’re brown and leathery. Pull out a piece and then try to break it: if it doesn’t snap like an old, dried twig, they aren’t done.

If that’s the case, put them back in the oven and check on them every 30 minutes or so, testing again until they are finished.

Step 9: Remove tray from oven, allow to cool. Take the tray out of the oven, turn it off, and then set it aside on the stove top or on a rack to cool. Once all of the peels have cooled down to room temperature, you’re ready to continue.

Step 10: Grind peels in blender. If your blender has a fine-grind attachment, install it now. Then, loading just a handful or two of the dried banana peels into the container, process them until they have reached a powdery consistency.

If the blender or food processor isn’t up to the task of grinding that fine, process them down as small as you can manage.

Shake the container periodically and stir before pulsing them again. Ideally, none of the pieces will be larger than a grain of rice once they are finished.

Step 11: Store powder in a glass container. Like all powdery substances, you’ve got to protect this stuff from moisture. Transfer the finished fertilizer powder into an airtight glass container until you are ready to use it.

Step 12: Finished! You are all done.

In the following sections, I’ll tell you how best to use your fertilizer powder in your garden or containers.

Using Your Fertilizer Directly in the Soil

The most straightforward and, for some of us, best way to apply our banana peel fertilizer is directly to or in the soil.

If you are transplanting or putting in started plants, you can add about a tablespoon of powder, or a little bit more, in the hole you have dug. Then simply plant normally and water to start dissolving the powder and making the potassium available to your plants.

This is a great way to give ornamentals, herbs, and vegetables a big boost of nutrition at the beginning of the season.

For established gardens, raised beds, and container plants, all you’ll need to do is sprinkle a tablespoon of the powder over the root area on top of the soil. Water normally and the potassium will make its way down to the roots.

This is the easiest and most direct method for giving your plants a little pep during times of stress.

Mix with Water, Eggshells, and Epsom Salt for a Convenient Spray

If you’d rather go with a liquid fertilizer solution, you’ll need the ground eggshells and Epsom salt I mentioned above in the supplies list.

Combine one tablespoon each of your banana peel powder, ground eggshells, and Epsom salt in a spray bottle or garden sprayer then add two cups of water. Stir vigorously or shake everything until all the ingredients are dissolved.

Spray the solution all over the soil at the base of your plants until moist or directly on them to give them a well-rounded boost of nutrients.

Wouldn’t it Be Simpler Just to Put the Peels in Your Garden Soil?

Before I let you go, there’s something I should address about using banana peels as fertilizer.

Some folks say that you can simply throw banana peels out into your garden or on your beds and let them break down to get the same effect as the one we’ve gotten here by processing the peels into powder.

After all, don’t people add banana peels to their compost pile, and when those peels break down, they release their nutrients? That’s true, but just throwing the peels out onto the ground and leaving them isn’t the same thing.

Because your peels decompose at an uneven rate and only add nutrients to the area where they are decomposing, this is woefully inefficient.

What’s worse, rotting banana peels stink and will attract flies, gnats, and other unwanted pests by the dozens or hundreds. Many of them are pests you don’t want hanging around your garden!

Don’t give in to the siren song of laziness: if you want to make use of banana peels as fertilizer, you need to process them.