My Easy Homemade Rose Fertilizer Recipe Ensures Huge Blooms for Years to Come – Plus, You Probably Have What You Need to Make It

Commercial rose fertilizers have their place, but they’re not the only option – and for gardeners who already have banana peels heading for the bin and coffee grounds on the counter, this brew costs nothing extra to make.

Each ingredient does a specific job. Potassium from the peels pushes bloom quality, nitrogen from the grounds keeps foliage dense and dark, and magnesium from the Epsom salt encourages new canes at the base of the plant, which mean more stems and more buds as the season goes.

It’s best to apply this homemade rose fertilizer at the right time for your particular plant, not the calendar. But rose gardens generally feed better in spring when new growth emerges and then again before the main flush in early summer. Here’s how to make my easy homemade rose fertilizer.

Step 1: Chop Up Banana Peels

You will need two or three old banana peels. Chop them into roughly 1-inch (2.5 cm) pieces before adding them to a jug. Smaller pieces mean more surface area in the water, which speeds up how quickly the nutrients steep over the next 48 hours.

Potassium is the nutrient most directly tied to flower quality in roses. It improves petal count, color depth, how long the blooms last. It's what most commercial rose formulas are built around, but banana peels that were heading for the trash deliver this vital nutrient well.

Step 2: Add Your Ingredients

Drop the chopped peels into a clean 1-gallon (3.8 L) jug. An old milk jug works perfectly for making this homemade rose fertilizer.

Next, add 2 tablespoons of used coffee grounds and 1 tablespoon of Epsom salt, which you can find at Walmart if you don't already have some on hand.

The coffee adds nitrogen, which drives green growth and keeps leaves from becoming thin and pale, plus it adds a mild acidity to the soil that suits roses. Roses tend to grow best in soil with a pH around 6.0-6.5. Used coffee grounds help nudge the pH in that direction without overdoing it.

The Epsom salt dissolves quickly and doesn’t need precise measuring. A tablespoon is roughly right, but a little over or under won’t change the outcome.

If your soil is already quite acidic, go lighter on the coffee grounds. The acidity contribution is mild, but it does build up with repeated applications so it’s worth keeping in mind if you reapply over a full season.

Step 3: Fill With Water & Let It Sit

Fill the jug with water, give it a shake, and set it somewhere out of direct sun. A cool corner of the garage or a shaded counter works well for the steep. Don’t leave it in a hot spot or direct afternoon sun. Leave it for 48 hours to sit.

The liquid will darken as the peels break down and everything steeps into the water. Tap water is fine to use, but if chlorine is a concern then you can leave the jug overnight before using it.

If you let this mix sit for longer than 48 hours, the organic materials will start breaking down past the point where they're useful. The smell is a reliable indicator to help you tell if your DIY liquid fertilizer has gone too far.

Step 4: Strain the Mixture

After 48 hours, strain the entire mixture through a fine mesh sieve or cheesecloth into a watering can. The liquid is what you will apply to your roses to give them a boost.

Removing the solids keeps the watering can spout clear and avoids leaving debris sitting on the soil surface around the plant to rot. A fine mesh strainer from Amazon handles this job well and it's useful in the kitchen for lots of other tasks, too.

The strained solids still have some value as organic matter and can go straight into your compost bin. The liquid doesn’t keep well, so making it in small batches and using it same-day or the next day is easier than trying to store a larger quantity. It’ll keep a day in the fridge, if needed, but not much longer than that before it loses its potency.

Step 5: Apply to Your Roses

Pour 2-4 cups (475-950 mL) around the base of each rose bush, spreading it over the entire root zone rather than pooling at the crown. Water roses lightly afterward if the soil is dry. This helps carry the nutrients down toward the roots so they can actually reach the nutrients they need, rather than letting everything sit at the soil surface.

Morning is the best time to apply fertilizer. Wet soil during a warm night can invite fungal problems – and roses don’t need any extra help in that department.

Apply homemade fertilizer every two to three weeks during the active growing season. The response will come gradually. Foliage will deepen in color, new canes will emerge at the base, and bud set will look a bit more substantial than the previous flush.

When applied consistently through the season, this homemade rose fertilizer is a low-effort way to keep feeding roses between between bigger fertilizer applications at the beginning or end of the season. This organic rose fertilizer from Espoma is a great option to use alongside my favorite homemade fertilizer for strong and healthy growth.

The best results tend to show up more in the second season than the first one when you start using my easy homemade rose fertilizer recipe.