Banana Peel Fertilizer: Does it Really Work? Here’s What You Should Know
Everybody loves money-saving DIY ideas, especially if it repurposes something that’s ordinarily trash. So, the idea to use banana peels as fertilizer seems, well, rather appealing (you knew we had to go there). But does this theory, popularized by social media, have any science behind it?
Before you start tossing banana peels on your houseplants or burying them in your garden beds, listen up: “It may make you feel like you’re doing some good, but there’s no great reason to use banana peels as fertilizer,” says Linda-Chalker Scott, PhD, professor and extension urban horticulturalist at Washington State University. “Non-composted materials are not a good way to introduce nutrients to the soil, and large pieces can attract pests or animals that will attempt to dig up the decomposing food.”
Here’s what else you need to know about using banana peel fertilizer:
Is banana peel fertilizer good for plants?
In a word, no. For starters, before you add anything to your soil you should know what’s already present so you can target the nutrients you actually need, says Chalker-Scott. An inexpensive soil test by your local university extension service (find yours here) can help you identify what’s missing, how much you should add and if you have too much of anything. Like most things in life, too much of anything isn’t good. “Plants can be damaged by too much of some nutrients, such as phosphorous, which interferes with the ability of the roots to take up iron,” says Chalker-Scott.
Do banana peels contain anything that’s good for plants?
Let’s review the basics: Plants need nitrogen (N), phosphorous (P), and potassium (K) to thrive.
“But materials have to be decomposed first so that they can release nutrients,” says Mussie Habteselassie, PhD, professor of soil microbiology at the University of Georgia. “Furthermore, the nutrient content may vary in banana peels, which means you would have inconsistent results, so you don’t really know what you’re adding to the soil.” In fact, one study looked at the how much of each beneficial plant nutrient banana peels contained and found that there were only miniscule amounts of N, P, and K. That means you’re contributing almost nothing useful to the soil, so you’re not really accomplishing anything.
Is banana peel water good for plants?
Another popular approach you may have heard about is to soak banana peels to make a sort of compost tea or banana water to be used as fertilizer. We hate to break it to you, but this doesn’t work either! “Any sort of compost tea is worthless,” says Chalker-Scott. “There are zero studies that show compost tea has a consistent positive effect. One study looked at the impact of compost tea on soil chemistry, such as the pH and nutrient content, and found it was no better than plain water.”
Banana peels actually could hurt your plants.
When buried, banana peels are slow to decompose. “You should have a balanced micro-organism environment in soil,” says Sam Schmitz, horticulturalist and supervisor of grounds operations at Ball Horticultural Company. “If other fungi are present in the soil, they could break down the peels and release non-beneficial chemicals that could start attacking living plant tissue.” You’re not much better off using it on plants indoors either, because rotting peels could attract pests such as fruit flies or may trigger smelly mold growth—neither of which is a pleasant experience. Finally, you have no idea if the peels contain pesticide residues, which could damage your plants.
But what about all the gardeners who say banana peels are good for plants?
In a nutshell, it’s all anecdotal evidence, not science-based studies that claim banana peels are good for plants. “One person’s experience with one or two plants doesn’t prove anything because the data size is too small,” says Schmitz.
What other organic fertilizer should I use?
“If you do want to feed your plants, you don’t have to experiment,” says Habteselassie. “Organic fertilizers are a known entity.” Look for those with the Organic Materials Review Institute (OMRI) seal, which ensures the product’s ingredients are in compliance with organic production methods.
Side note: It’s worth mentioning that organic fertilizers can be smelly because they’re derived from plant and animal sources. While the odor fades, pets may be attracted to both liquid and granular types. In fact, organic fertilizers regularly make ASPCA’s list of top 10 toxins because they can cause vomiting, tummy upset, and seizures if ingested. Keep your fur babies safe by fencing in your garden, keeping potted plants out of reach, and not leaving organic fertilizer or any other garden products where pets can get to them.
Finally, as for all those banana peels you’ve been saving, they’re not totally worthless. The bottom line is you’ll do better by tossing them into a backyard compost pile or bin. “Let nature do the work of creating healthy compost you can use on plants in the future,” says Chalker-Scott.
This news may be a bummer, but don’t be discouraged. Consider these products to make use of those peels—and create a healthier environment for your plants.