If you’ve ever flinched at the price of shiny bottled cannabis fertilizers, you’re not alone. Many growers now look for low-cost, sustainable alternatives that don’t sacrifice quality. One of the best options is the humble banana peel, an everyday kitchen scrap that can be transformed into a powerful organic fertilizer.
With a little know-how and minimal effort, you can create a homemade nutrient mix that rivals commercial products. In this guide, you’ll learn why banana peels are so effective, how to make banana peel tea for cannabis, when it works best, and when it doesn’t. You’ll also find a few honest grower experiences and answers to common questions.
Why Use Banana Peel Tea for Cannabis?
Every cannabis plant relies on three main macronutrients: nitrogen (N), phosphorus (P), and potassium (K). During the vegetative stage, plants crave more nitrogen to build strong stems and leaves. Once flowering begins, phosphorus and potassium take the lead, helping produce bigger, denser buds.
Banana peels naturally contain around 42% potassium and just over 3% phosphorus, making them a perfect addition during the flowering phase. Potassium strengthens the plant’s immune system, improves drought resistance, and boosts yield quality. Phosphorus supports flower and root development, giving you fuller, more resinous buds. Studies published by the Journal of Plant Nutrition and Soil Science confirm that potassium plays a vital role in enzyme activation and photosynthetic efficiency, directly influencing crop productivity.
Research published in Plant and Soil and the Journal of Agricultural and Food Chemistry shows that banana residues contain polyphenols and natural sugars that stimulate beneficial soil microbes. These microbes help release nutrients more efficiently, improving root health and overall plant vigor. This biological interaction can also support better aroma development in some grows.
Nutrient Breakdown of Banana Peels
Banana peels are loaded with potassium and phosphorus but contain almost no nitrogen, which is why they’re most effective during flowering rather than early growth. Here’s a quick nutrient overview:
| Nutrient | Content (%) | Role in Cannabis Growth |
|---|---|---|
| Potassium (K) | ~42 | Improves bud density and terpene production |
| Phosphorus (P) | ~3 | Supports flower formation |
| Calcium (Ca) | ~1 | Strengthens cell walls |
| Nitrogen (N) | <1 | Needed mostly in vegetative phase |
This simple balance explains why banana peel tea works best as a bloom booster, not a full fertilizer.
How to Make Banana Peel Tea
Making banana peel tea for cannabis is simple, eco-friendly, and gives you an excuse to enjoy a banana every day. You only need two ingredients and a few household items.
Ingredients
- Banana peels (wash thoroughly before use to remove any residues)
- Water (distilled, rain, or spring water is best)
Before using, rinse the banana peels well under warm running water. This helps remove any wax, pesticide traces, or surface dust, ensuring your homemade fertilizer is clean and safe for your cannabis plants.
Equipment
A large glass jar or pitcher (around two litres), another jar for storage, a tea towel, a fine strainer or cloth, scissors, and a fridge.
Step 1: Prepare the Water
Fill your jar about three-quarters full with clean water. Filtered or distilled water ensures no unwanted chemicals interfere with your mix. Cover the jar with a tea towel and keep it in the fridge.
Step 2: Chop the Banana Peels
After eating your bananas, cut the peels into small half-inch pieces with scissors. Drop them into the jar of water. Keep adding until the jar is about one-quarter full of peels.
Step 3: Let It Infuse
Refrigerate the mixture for one to two days, stirring twice daily. This allows the nutrients to infuse gently into the water without fermenting.
Step 4: Strain and Store
Once the water has turned a light golden color, strain it through a fine cloth or sieve into your second jar. You now have a concentrated organic cannabis fertilizer ready to use. Save the used peels - they’ll come in handy later for your homemade rooting aid or compost.
Save the used peels! Later in this article, we'll show you how to convert them to an organic rooting aid. If this is not something you require, they can now be turned into compost.
How to Use Banana Fertilizer on Cannabis
Banana tea is nutrient-rich, so it should always be diluted before use. Mix one part banana peel fertilizer with ten parts water (1:10 ratio). Use it as you would any liquid feed, either through watering or light foliar spraying.
Make sure the solution is free of solid bits, especially if using a spray bottle, as residue can clog nozzles and attract insects indoors.
If you choose foliar feeding, use only well-strained banana tea without any additives and spray early in the light cycle, then improve air movement to reduce residue and pest risk.
Don't Overdo It
Too much potassium can cause nutrient lockout, preventing your plants from absorbing other key elements. Start light and observe how your plants respond before increasing the dosage. According to research published in ScienceDirect, excessive potassium levels can interfere with the uptake of calcium and magnesium, leading to visible nutrient deficiencies.
When to Apply
You can use banana peel fertilizer about halfway through the vegetative stage to build early strength, then again around week four of flowering when potassium demand peaks. A final light dose during late flowering can also support resin and terpene production. Use sparingly and adjust based on your strain’s needs, as some potassium-hungry varieties can handle more than others.
Pairing Banana Tea with Other Organic Boosters
Banana peel tea works best when used alongside other gentle organic supplements. To maintain a balanced nutrient profile, pair it with:
- Molasses: Adds natural sugars that feed beneficial microbes and enhance nutrient absorption.
- Compost tea: Provides nitrogen and micronutrients missing in banana peels.
- Seaweed extract: Adds trace minerals and helps boost terpene expression.
For example, mixing one tablespoon of unsulfured molasses per litre of water along with banana tea can noticeably improve microbial life and nutrient uptake. Add molasses to the final watering mix after you dilute the banana tea at 1:10, not to the concentrate. Avoid foliar spraying when molasses is in the mix.
The combination gives cannabis a more robust flowering response without resorting to synthetic boosters.
When Banana Peel Tea Is Not the Right Choice
Banana peel tea is a great supplement, but it’s not a complete fertilizer. It lacks nitrogen, calcium, and other micronutrients essential for balanced cannabis growth. Over-relying on banana tea can lead to deficiencies, especially in young plants that need more nitrogen.
Avoid using banana peel tea:
- During early vegetative growth, when nitrogen demand is high.
- In hydroponic systems, where organic matter can clog pumps or cause bacterial buildup.
- If you already use potassium-rich fertilizers, as this may create nutrient imbalance.
Another practical concern is hygiene. Like any organic feed, banana tea should be stored properly and used fresh to prevent unpleasant odours or attracting pests. Always strain it well and keep it in a sealed container in the fridge for up to three days. If your grow space already has fungus gnats, fruit flies, or other insects, it’s best to avoid banana tea until those pests are under control, as its sweet scent can make infestations worse.
Banana Peel Tea vs Commercial Fertilizers
Banana peel tea shines as an eco-friendly, short-term boost during flowering, while commercial fertilizers offer full nutrient balance and consistent performance. Many growers combine both - organic supplements like banana tea plus a base fertilizer for stable results.
Bonus Recipe: Banana Peel Root Aid
Don’t throw away those peels. Once dried, they can be turned into a natural rooting powder to help clones develop strong roots. Add coffee grounds or nuts to boost nitrogen and phosphorus levels.
Step 1: Dry out banana peels
Lay banana peels out in the sun, use a food dehydrator, or set your oven to its lowest temperature. They’re ready when crisp and dry.
Step 2: Grind into Powder
Blend the dried peels into a fine powder using a coffee grinder or mortar and pestle. Add a tablespoon of dried coffee grounds and four or five Brazil nuts or almonds, then grind again until combined.
Step 3: Apply as Rooting Aid
Mix half a teaspoon of powder into the soil where you’ll place your cutting. Then make a paste from another half teaspoon mixed with a few drops of water. Dip the cutting into the paste so that about one centimeter of the stem is coated before planting. This simple trick can significantly boost root growth naturally.
Grower Experiences
Organic growers often praise banana peel tea as an easy and satisfying DIY addition. On cannabis forums, users report noticeable results in flower density and aroma, though not all experiences are positive.
- “My soil was so out of whack after I used it. Had to buffer it waaaay back up.” - r/cannabiscultivation
- “I chop up 3-4 banana peels … then drop into the jar and reuse in flower.” - r/Autoflowers
- “Banana peels are a good source of potassium, but it takes so long to break down it may not give your plants the nutrients in time.” - r/CannabisGrowers
- “If you take a banana and slice it, then cover it in brown sugar, you’re into some awesome plant soil food.” - r/NoTillGrowery
- “Banana peels have one of the highest organic sources of potassium. Potassium helps plants move nutrients and water between cells.” - r/microgrowery
These first-hand stories highlight what the science already shows: banana peel tea works best as a targeted supplement, not a full replacement.
FAQ
Can I use banana peel tea in hydroponics?
It’s not recommended, as organic residues can clog systems and promote bacterial growth.
Can I store banana peel tea for later use?
Yes, but keep it refrigerated and use it within 2–3 days. Beyond that, fermentation may begin.
Does banana peel tea attract insects?
Yes, it can increase pest pressure, especially fungus gnats and fruit flies, because of its sugars and sweet scent. The risk grows if you use foliar sprays, leave residues on the surface, overwater, or include peel solids. Reduce the risk by straining very finely (coffee filter or 100–200 µm), applying only to the root zone, watering in so there’s no runoff, improving airflow, and refrigerating the tea for no longer than 48–72 hours. Discard if it smells sour, turns cloudy, or foams. If you already have gnats, skip banana tea until the infestation is controlled.
Can banana peel tea improve cannabis flavour?
Many growers report slightly sweeter, fruitier terpenes when used during mid-to-late flowering, though results depend on strain and soil composition.
Is banana peel tea enough on its own?
No. It’s a great booster during flowering but not a complete nutrient source for all growth stages.
Should You Make Banana Peel Fertilizer?
If you’re growing organically or simply want to save money on bottled nutrients, banana peel tea is a smart and sustainable choice. It recycles kitchen waste, enriches your soil with vital potassium, and supports stronger growth throughout flowering. Plus, you get a free rooting aid from the leftovers.
For beginner growers, this method is one of the easiest ways to learn about plant nutrition while keeping your grow eco-friendly. Sometimes the best cannabis fertilizers don’t come from a store - they come straight from your fruit bowl.