Roses are deciduous plants known for their showy, often fragrant and colorful flowers that range in shades from white and peach to bright orange and deep red.
But, something which all roses have in common is their preference for well-nourished soil. It’s understandable, then, that gardeners often look for natural ways to enrich growing conditions.
That’s where coffee grounds come in. In the right situations, leftover coffee grounds can be put to good use, offering several benefits, especially when growing roses.
Why People Use Coffee Grounds in the Garden
Used coffee grounds—what’s left after brewing—contain moderate amounts of nitrogen and smaller traces of potassium, magnesium, and other minerals.
They’re also rich in organic matter, which means they can improve soil texture and structure as they break down. These properties make them appealing to those aiming to reduce waste and boost soil health.
Some gardeners also note a minor repellent effect on pests like slugs, though how you use coffee grounds in your garden will change depending on whether the focus is as a soil improver or pest repellent—we’ll touch on this later.
What Coffee Grounds Can Do for Roses
Roses are considered heavy feeders and do well with regular access to nutrients to support their quick growth and abundant flowering. Coffee grounds are rich in nitrogen, which supports leaf growth, and also contain potassium, which enhances resilience.
However, roses also need phosphorus, as well as other trace nutrients, to flourish, particularly when it comes to flowering. Because of this, coffee grounds cannot be used as the sole source of nutrition for roses.
Perhaps more reliably, used grounds can help with soil structure. When incorporated correctly, they may improve drainage and aeration in heavier soils.
That said, they must be applied with care—grounds are very fine in texture and can become compacted or waterlogged if layered too thickly or used fresh.
How to Use Coffee Grounds Around Roses
The most effective way to use coffee grounds is to add them to a compost pile. For those choosing to use coffee grounds directly, a few points are worth noting:
Important: Avoid pouring leftover liquid coffee directly onto your roses, as it is much more acidic than just the grounds alone. Although roses enjoy mildly acidic conditions, they are not acid-loving plants, so we want to avoid creating overly acidic conditions.
Using Coffee Grounds as a Pest-Repellent
To repel slugs and snails, the grounds can be scattered around the base—this time not worked into the ground as the repellent qualities will be most effective when left on top of the soil.
Take care not to layer thickly or too close to the stems of your roses.
Important: Consider that coffee grounds applied in this way will not provide the same soil-enhancing benefits as when composted or incorporated into the soil.
How Much Is Too Much?
Coffee grounds are best used in moderation. As a rule of thumb, a small dose once a month is ample for established roses.
The aim is always to support soil structure and nutrient content without overwhelming it. If you have a surplus of leftover coffee grounds in your kitchen, your best option is to add them to your composting heap.
What Gardeners Recommend (and What They Avoid)
Rather than seeing them as a fertilizer in their own right, most seasoned growers use coffee grounds as a light soil conditioner or compost ingredient. The following practices are recommended:
Other Natural Boosts for Rose Health
The following ‘ingredients’ can also be used as part of a balanced care practice for your roses:
Final Thoughts
While coffee grounds don’t offer a miracle cure or dramatic transformation, they can be a useful part of rose care when used in the right way. Their value lies less in quick nutrition and more in gradual improvement of soil texture and fertility.
However, it is important not to use them as the sole fertilizer, but rather alongside a balance of all the nutrients your roses need.
Composting coffee grounds is the most effective and reliable way to put coffee grounds to good use for your roses, helping to form part of a low-input, sustainable approach to growing—and for many gardeners, that’s reason enough to make use of what’s left in the bottom of the cafetière.
