Most gardeners are already familiar with composting. Turning all kinds of organic kitchen scraps into nutrient-rich fertilizer is a time-tested technique for producing a bumper crop of fruits and veggies in your garden, or just getting some truly stunning ornamentals.
But what you might not know is that it is possible to use just a single “ingredient” to make beneficial and versatile fertilizer.
Some of the best kitchen scraps for this purpose are banana peels. Yep, that’s it! Banana peels are extremely rich in potassium, but you’ve got to know how to prepare them for optimal results.
And don’t worry: making banana peel fertilizer is a lot easier than you think and a whole lot quicker than waiting for a compost pile to break down. I’ll tell you everything you need to know and how to do it step by step in this guide.
What Can Banana Peels Do for Your Plants?
As mentioned, banana peels are a wonderful source of potassium. Potassium, the K in the quintessential NPK fertilizer ratio, is a crucially important nutrient that helps all plants develop strong root networks and also produce both fruit and blooms.
Without it, your plants simply won’t perform well because they will lack the substantial roots needed for stability, health, and moisture absorption, and because what fruit, veggies, and flowers they produce will be stunted and puny.
It will be a shame to put in all this work and time for a meager return!
Banana peels make a wonderful source of potassium because they are natural, easy to handle, and very easy to use once you process them.
No nasty chemicals, horrible smells, or potent concoctions that stand a high chance of harming your precious plants.
Can’t You Just Toss Banana Peels Out and Let Them Decompose?
You can, but you really shouldn’t, even though some folks still recommend this approach in our day and age. I strongly advise against it!
Although this method is certainly tempting for those of us who are very busy, or just lazy like me, it’s going to cause more harm than good…
Throwing out banana peels and letting them decompose in the garden is an extremely inefficient way to get usable potassium into the soil where your plants can absorb it.
Worse, the aroma is bound to attract pests that you don’t want hanging around, including all kinds of rodents, bugs, and more.
If you try this, you really are just leaving rotting garbage lying around your garden and the results will reflect that.
By spending just a little bit of extra time and hardly any real effort into prepping the banana peels, you’ll turn them into a ready-to-use soil amendment that works much better for pumping up those potassium levels.
What You’ll Need
You don’t need very much at all to make banana peel fertilizer. Grab the following and you’ll be ready.
Banana Peels: obviously, we will need the peels as our base and, often, only ingredient! But if you want to add fertilizer to anything but one or two potted plants, you’ll need lots of peels.
Collect anywhere from 15 to 30 banana peels before you get started. You don’t have to collect them all at once if you store them properly, and I’ll tell you how to do that below.
Also, if at all possible, get organic banana peels; the pesticides that they are invariably treated with can have negative consequences for the health of your plants and beneficial microorganisms otherwise.
Food Dehydrator or Oven: this is the trick to making banana peels fertilizer quickly and easily. A common food dehydrator or, lacking that, your oven will dry them out quickly and easily.
Food Processor: once dried, we’ll grind the peels into tiny bits or powder using a food processor. You can do this by hand, but it’s slow and very laborious. In my experience, even a basic blender does a good job, so make sure you have one.
Paring Knife: any sharp paring knife will help you cut the peels down to size.
Cutting Board: a plastic or wooden cutting board works just fine here.
Ziploc Bag, extra large: chances are you’ll want to store up a good quantity of peels before you process. My preferred method is to just stash them in a jumbo Ziploc bag in the freezer so they don’t rot. Don’t worry, they won’t smell!
Freezer: freezing your accumulated banana peels will let you keep them on hand and intact until you are ready to process.
Epsom Salt (optional): you can use the peels by themselves as an effective, potassium-only fertilizer that will add a few other trace nutrients, but it can be particularly effective when combined with Epsom salt for magnesium, which potassium tends to be antagonistic toward.
This is up to you if you want to use it or not, and I’ll tell you how after the step-by-step…
Calcium Carbonate or eggshells (optional): likewise, adding some calcium carbonate to your fertilizer mixture can provide better-rounded nutrition that will be more steadily absorbed by your plants.
You can procure fertilizer-grade stuff that’s ready to add, or make your own from ground eggshells.
Preparing Your Banana Peel Fertilizer, Step by Step
Step 1: portion out banana peels. If you’ve been collecting peels for a while, pull out however many you need based on how much fertilizer you are making.
One complete peel from a large banana will make about one tablespoon of potassium-rich fertilizer. Cut off the woody cap and stem from each peel. Throw those away, or into your compost bin…
Step 2: thaw banana peels. Take your banana peels out of the freezer and lay them on your cutting board to thaw. It won’t take long at room temperature, maybe 30 minutes.
Step 3: slice peels into sections.
Then slice each section of each peel into chunks that are no more than a few inches long and wide. This will help them dry out more quickly and evenly, and make later processing easier.
Step 4: place peel pieces on the dehydrator tray or baking sheet. Load each of your pieces onto your dehydrator tray or a baking sheet depending on whether or not you’re using your food dehydrator or oven.
Make sure they aren’t touching and aren’t overlapping, but as long as they have a little space between them you can pack in as many as you can fit
Step 5: load and set temperature. Place the peels in your food dehydrator or oven. If using a food dehydrator, set the temperature between 145°F and 150°F. If your oven will go that low, do that, otherwise set it as low as it can and leave the door cracked.
Step 6: set timer. Set a timer for around 6 hours if you have the temperature very low. If your oven only goes down to 200°F, set it for 5 hours or 4 hours for 300°F.
Step 7: check peels for doneness. Every couple of hours, check on the banana peels; they should be shrinking drastically and curling up slightly. Test one if you need to.
Once they are deeply browned throughout like leather and snap cleanly like a twig without bending, they are ready. IMG_8570
Step 8: set aside to cool. Once the peels are dry and crispy, turn off your appliance, pull them out, and set them aside so they can cool back down to room temperature.
Step 9: grind. Working in small batches so you don’t overload your food processor, pulse the peels with the appropriate blade or attachment until you achieve a powder consistency.
If your food processor won’t quite manage that, keep at it until the banana peel bits are about the size of rice grains.
Step 10: store. Keep your ground banana peel in an airtight glass container for best results if you aren’t using it immediately.
And that’s it, you are finished!
By taking these simple steps, you’ve turned banana peels into fertilizer that can quickly and easily be absorbed by your plants to supply much-needed potassium on demand.
I’ll tell you how best to apply it in the following section…
Four Ways to Use Your Banana Peel Fertilizer
Direct Application
Direct application is one of the easiest ways to use your DIY fertilizer, especially if your soil test reveals that your plants just need potassium.
You can add a teaspoon or a tablespoon or a little more directly around the base of each plant. Water it in, and the powder will break down quickly, making the potassium available to your plants’ roots.
Before Planting
Alternatively, if you’re starting out with new plantings, you can add the same amount of powder to the bottom of the hole and then cover it with a thin layer of soil so it won’t be in direct contact with the plant.
Water normally to give your plants a big boost of nutrition early in the growing season.
To Prepare Soil
Lastly, you can mix your banana peel powder with other organic soil amendments to fortify your soil ahead of or at the end of the growing season to help get it ready for next season.
The amount you use will vary, of course, depending on how depleted your soil is, but a good policy is to add it conservatively and then test the following week before adding more if needed.
In a Solution
One of my very favorite ways to use banana peels is as part of an all-purpose fertilizer solution:
This is where the calcium carbonate and Epsom salt come in. Simply mix one part of your ground banana peels, one part of calcium carbonate or ground eggshells, and one part of Epsom salt to 30 parts of water before stirring everything together briskly.
Ideally, everything will be totally dissolved but at the very least make sure the salt fully dissolves.
Load the solution up in a spray bottle, garden sprayer, or watering can and apply directly to your plants or soil as needed to give them a little shot of nutrition during stressful times or whenever they are starting to slump.
Don’t forget to pin this on Pinterest using the image below… And if you want a more “advanced recipe” check out how to make a fertilizer banana “tea”.
Tim is a farm boy with vast experience on homesteads, and with survival and prepping. He lives a self-reliant lifestyle along with his aging mother in a quiet and very conservative little town in Ohio. He teaches folks about security, prepping and self-sufficiency not just through his witty writing, but also in person.
Find out more about Tim and the rest of the crew here.