It’s a hobby of mine to use zero-waste ideas to accomplish a goal. I’ve made a delicious syrup from my strawberry tops that I use to flavor my homemade kombucha. I’ve also made fantastic croutons from my stale bread. Homemade fertilizers made from things I’d normally throw away (or compost) are my present interest.
Banana peels make a great liquid homemade fertilizer to provide essential nutrients to our potassium-loving plants. I used the liquid for a while, but now I have all of my gardens on a timer. The watering schedule is no longer reliant on me because it is now controlled by a timer at the spicket. This eliminates the need for me to hand-water my plants, so I made up a new homemade fertilizer that would work better for my system.
Most plants need a certain amount of these top three macronutrients: nitrogen, phosphorus, and potassium. Some plants are more needful of nitrogen, while others are more needful of phosphorus, and still others need a higher level of potassium. I’m going to show you how to make your own banana peel fertilizer, and I’ll have a list of which vegetables to use it with available to you at the bottom of the post.
How I Made My Homemade Fertilizer from Banana Peels
My family goes through bananas quickly, so I always have plenty of peels to take outside to my handy-dandy electricity-free dehydrator. I leave them in there a few days until they are black and brittle. If you don’t have one of those, you could just leave them outside in the sun.
This is what they look like after they are dried. I forgot to take the stickers off, but I’m glad because it reminds me to tell you that if you are putting this fertilizer into your organic vegetable garden, you’ll want to make sure you are buying organic bananas for this project. If you aren’t specifically organic in your gardening, then it’s no worries. There is still plenty of lovely potassium to be had in non-organic peels.
Next, I bring them indoors and cut them with my kitchen shears into half- to one-inch squares. This makes the pieces small enough for my bullet blender (here’s a better version of a bullet blender–mine is really old). I whirl them around until they are almost the consistency of coarse pepper. There are still a few little stringy bits in there, but that’s alright.
Each dried banana peel makes 1-2 Tbsp. of fertilizer, depending on the size. Many people will bury a banana peel near the roots of a potassium-loving plant, so I think it’s safe to say that 1-2 Tbsp. of this fertilizer around your potassium loving plants will be enough. Use as often as you would use any other fertilizer for your potassium-loving plants, but since this one is mostly potassium, you will want to find out if the plant you are fertilizing has any nitrogen or phosphorus needs as well, and fertilize accordingly.
If you don’t know which plants are potassium-loving, you can get my “Common Vegetable Garden Plant Info Sheet” which lists the potassium needs of each plant commonly grown in spring and summer. It’s in my resource library, and you can get the password to it at the bottom of this post.