Using Coffee Grounds Good For Roses? The Good & The Bad

If you are an avid coffee drinker, and you love your garden, chances are you are using spent coffee grounds in your garden in some shape or form. It is no secret, used coffee grounds can provide your soil with a nutrient boost your plants will appreciate – but is this a universal rule for all plants? Are coffee grounds good for your roses?

Roses will enjoy the boost in nitrogen and slight acidity used coffee grounds can deliver to the surrounding soil. However, as is most things in life, the key is moderation. If your soil is already acidic or has already been enriched with fertilizer high in nitrogen, adding coffee grounds could cause an imbalance. Roses growing in acidic soil will have stunted growth, while too much nitrogen in the soil can cause fertilizer burn.

Are Coffee Grounds Good for Roses

Welcome to the Garden Bench Top, where in today’s article we are going to discuss the positive and negative impacts coffee grounds can have on your prized roses. We’ll also touch on the various ways you can use coffee in your garden, and a few other considerations that you should be aware of when combining coffee and your garden.

So if you are ready, grab that hot cup of coffee, and get ready to learn a thing or two.

Why are Coffee Grounds Good for Roses?

As we mentioned earlier, there are a number of benefits your beautiful rose bushes can procure from used coffee grounds. Let’s take a closer look at these benefits.

rose bushes with coffee grounds

Valuable Nutrients Galore!

Roses need a variety of nutrients and minerals in order to grow into healthy plants with prolific blooms. Some essential minerals roses require include nitrogen, potassium, phosphorus and copper.

And, as you can probably guess, used coffee grounds possess all these minerals and is an excellent source of nitrogen (the primary mineral for healthy plant growth. It can provide a welcomed boost of all these elements when added to your roses’ soil.

Increases Acidity of the Soil

Spent coffee grounds have a slightly acidic composition between 6.5 to 6.8 pH level. And by adding it to your garden soil, you can manipulate the pH levels to create a more acidic environment.

Guess what type of soil roses prefer? That’s right – they love a soil acidity that hovers around 6.5. Your roses will thrive in soil slightly above or below, as long as it stays around this level.

Boost Organic Material

Used Coffee in Compost Pile

Another pro for adding spent coffee to your soil or your compost is that you are building up the organic material in your soil.

Rather than adding artificial pre-packaged materials that you source from your local nursery, try reusing the organic waste from your day-to-day. Not only will the environment thank you (by reducing landfill), the microorganisms in your soil will appreciate the added waste materials (their food).

We like to add small amounts of used coffee ground to our worm farms to provide them with a variety of organic material to eat. It also helps to process and breakdown the used coffee grounds faster, compared to adding it directly to the soil of rose plants.

Are Used Coffee Grounds Bad for Roses?

Before you race out and begin dumping all your coffee waste onto your rose bush beds, there are some considerations that you need to be made aware.

We can see your mind ticking over saying ‘Hang on, after all the benefits you listed above, how could there be any bad effects on my roses? ‘

We’re not saying don’t use coffee grounds in your garden or your roses. It is more a matter of how much you should add to your garden with used coffee grounds.

Adding spent coffee grounds to your soil is only good in moderation. Too much can be detrimental.

Fertilizer Burn – Overdose of Nitrogen

As we mentioned above, used coffee has high levels of nitrogen. If you are already dosing your garden soil with nitrogen rich fertilizer, this could lead to problems for your roses (and other plants for the matter).

Too much nitrogen in the soil is classified as an over-fertilization and can result in fertilization burn on the roots of roses.

You’ll be able to recognize fertilizer burn on your rose bushes if the leaves develop brown patches that turn crispy. You may also see black streaks developing on the veins of the leaves and parts of the stem close to the leaf nodes.

When to Add Coffee Grounds to Roses for Optimal Growth

Besides monitoring how much coffee grounds to add to your roses, another consideration you need to take into account is the timing of when you add coffee grounds.

If you are adding spent coffee grounds to the topsoil of your roses’ soil, we recommend adding the coffee grounds towards the end of winter or early spring. This way, the microorganisms will have time to process the used coffee grounds in time for the roses to absorb the nutrients.

On the other hand, if you are adding coffee grounds to your compost, the timing of when you add the coffee to your compost is not as essential. As long as you give your compost pile enough time to do its thing and go through the motions of decomposing.

Again, when you add the nutritious compost fertilizer to your roses, it is the important element here. Again, add compost to your roses at the beginning of the growing season for optimal growth and nutrient uptake.

Instructions For How To Use Coffee Grounds For Roses

Used Coffee Filter for compost

Okay, so now you have the low down on how much and when to use spent coffee on your roses, let’s not go through the motions by working our way through a step-by-step process.

  1. Source Your Coffee Grounds – Using freshly brewed coffee grounds from your choice of brewing method (filter, espresso, pressed or even coffee shops), pour it into a container and crush it up. It is important to not let the grounds age for longer than a day (24 hours). Old grounds can develop bacteria and attract mold, which will be transferred to your soil.
  2. Add to Soil or Compost – Using the broken up coffee grounds, you can sprinkle them evenly into your compost pile directly. Note, if you are using paper coffee filters, then feel free to add these to your compost pile, as they are biodegradable.

    Or you can add the coffee grinds directly into the topsoil of your rose beds. If you are adding it directly to your roses, make sure it is done towards the beginning of the growing season. Also, ensure you mix it into the soil and not just allowed to sit on top of the soil. This way, the microorganisms will be able to access the coffee and process it to release the essential nutrients.

  3. Dilute with Water – Another popular method of using coffee grounds is to create a coffee fertilizer. Combine your grounds with 2 gallons (around 7 liters) of water. Mix vigorously until it taints the water into a diluted coffee liquid. We like to let the coffee grinds sit for a few hours to soften further. Use the mixture on your rose garden and other plants.

Other Considerations When Using Coffee Grounds for Roses

Coffee grounds have other side benefits, other than just fertilization purposes. Here are a few more perks used coffee can help with in your garden.

Do Coffee Grounds Help Get Rid of Ants on Roses?

Coffee grounds are a natural repellent against ants. By sprinkling used coffee grounds around your roses, it will deter them from climbing onto your roses or using them as a thorough-fare to other parts of your garden, like your vegetable patch.

Unfortunately, the repelling effect is only effective while the used coffee grounds are fresh. To keep them at bay, you will have to reapply the coffee grounds, which can lead to other problems like an excess of nitrogen which we discussed earlier.

Do Coffee Grounds Attract Worms?

Worms are attracted to any decomposing organic material in the soil – this includes spent coffee grounds. It is their food source, and they will seek it out to consume.

Worms are a gardener’s best friend. They help to aerate the ground as they munch their way through the soil. Plus, their poo (worm casts) are full of vitamins and minerals that plants love to absorb.