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Are Coffee Grounds Good For Roses? Here Are 5 Myths And Facts

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Rose Plants and Coffee Grounds

Do you have a corner for rose plants in your garden? Or, are you planning to plant some rose bushes? After all, who does not like roses? Their sweet fragrance and riot of colors can make anyone a romantic. There are many tips for growing great flowering rose bushes and it may confuse you.

When I started growing roses I tried many things. Some worked and some did not. I spent a lot of money on expensive fertilizers. Then someone told me about using coffee grounds.

Instead of spending a lot of money on these things, you can try something readily available at home. Coffee grounds have been touted as a great way to use a waste product to fertilize rose plants effectively.

However, like everything else, there are some benefits and some drawbacks. To answer the question, are coffee grounds good for roses, let us look at some facts.

Are Coffee Grounds Good For Roses

Are Coffee Grounds Good For Roses?

What exactly do coffee grounds do for a rose bush that is beneficial to them?

  • The main reason why coffee grounds are good for rose plants is because of the high nitrogen content.
    • Especially in the spring, at the start of the growing season, it ensures a healthier plant.
    • Apart from nitrogen, there are other essential minerals like phosphorus, potassium, and copper, and all of these help make the soil healthier and provide valuable nutrients to the rose plant.
  • Roses need slightly acidic soil for healthier growth.
    • Coffee grounds are acidic and can lower the pH level of the soil.
    • Though different coffee beans have distinct acidity, most of them are generally pH neutral to slightly acidic once decomposed.
    • This is perfect for rose bushes. It is advisable to check the pH level of soil before adding coffee grounds.
  • Coffee grounds also help in loosening the soil, which allows the roots to grow better and deliver the nutrients.
    • Organic materials like coffee grounds improve the soil structure and also enable earthworms and other microbes to thrive.
    • This process allows for better absorption of water and letting excess water drain freely. Rose bushes require well-drained soil to grow well.
  • It also makes for a good repellent. Some bugs and pests which can otherwise damage the plant can be repelled with coffee grounds.
What exactly do coffee grounds do for a rose bush that is beneficial to them
Composting worms moving about in used coffee grounds.

How Can You Effectively Use Coffee Grounds?

There are different ways in which you can use the coffee grounds to fertilize your rose bushes. One thing to always remember is that you must use coffee grounds in moderation. Using too much can cause problems which we will look into later in the article.

Coffee grounds can benefit your rose bushes, but only if you do it right. Here are three easy ways to use coffee grounds for maximum benefit. Watch this video for more information.

1. Sprinkle around The Plant

The simplest way is to sprinkle the coffee grounds at the base of the rose bush. By sprinkling, about half a pound of coffee grounds around the rose plant can increase the nitrogen content.

You don’t have to dig as it may disturb the roots. You should add water to let it seep in. For half a pound of grounds, you will need to use 2 gallons of water.

The worms also play their part by ingesting and working the coffee grounds into the soil. Rose beds with a lot of worm activities point towards healthy soil and good growing conditions.

The best time to do this is at the start of the growing season. If you fertilize too late, it may be very harmful to the plant.

2. Mix Coffee Grounds and Water

Mix about half a pound of coffee grounds in 2 gallons of water. Standard watering cans have a capacity of about 2 gallons. Make sure that the coffee grounds are mixed well with the water.

Now water the soil surrounding the rose bushes. The plants get even distribution with this, and you will not have to water separately.

Put the coffee grounds into the watering can before you fill it with water. Make sure it mixes evenly throughout.

Ground coffee in boxes - Are Coffee Grounds Good For Roses

You have an effective fertilizer in this mixture. It goes deep into the soil and reaches the roots. Use this only at the start of the growing season.

Any late season growth can be damaged at the beginning of winter. The dilution ratio has to be right; otherwise, the plant may get damaged.

3. Add Coffee Grounds to Compost Heap

Another way of using coffee grounds is by mixing it with your compost. Applying compost around the rose plant will help in suppressing weed growth and increasing drainage.

Soil structure improves with the appropriate mix of nitrogen and carbon. Coffee grounds are organic, and any organic mulch is excellent at absorbing water. Roots of the rose plants can easily draw upon this stored moisture when needed.

Coffee and compost mixture is best applied at the start of spring. It is at this time that weeds start to grow and compete with rose plants for nutrients.

You don’t have to dig to add mulch. Digging can damage the roots. Just spread the mulch around the rose bush at a depth of 1 or 2 inches.

Worms and water will take it to the roots. Don’t pile too much of the mulch around the stem as it may cause rot. One inch of the radius around the stem should be clear.

Where to Get Coffee Grounds From?

What to do if you are not a coffee drinker? Or, only an occasional drinker! Well, here are a few ways you can get your hands on coffee grounds.

  • Ask friends to save their coffee grounds and then collect them. You can do the collection weekly or monthly, depending on where they live.
  • Go to a local restaurant or coffee shop and ask for old coffee grounds. For them, it is waste, and they may give it to you for free. Bigger coffee shops have stricter policies about waste disposal, and they may not be willing to hand over the coffee grounds.
  • Grow them yourself! In this case, you’ll only face some difficulties if you live in colder climate like in the UK. Can you grow coffee in the UK? Well…see for yourself.

Best Time to Use Coffee Grounds

When applying coffee grounds is an important question. Coffee grounds have nitrogen as the primary nutrient, which is perfect for fertilizing rose plants.

However, if the timing is not right, then you may not get the desired results. Too early or too late in the season, and you will end up with a damaged rose bush.

April and May are ideal months because this is when the rose is coming out of its winter dormancy, and new leaves are opening fully. It is best not to spread coffee grounds after mid-August. The rose plant and its further growth need time to prepare for the coming winter months by hardening up.

When you apply coffee grounds too late, it stimulates new growth, which is delicate and cannot face the severity of winter months and frosty conditions.

Invariably the new growth will turn black and die. If this happens, you must act quickly and cut the dead portion out before it affects the complete bush.

Are There Any Harmful Effects of Coffee Grounds?

The main harm that can be caused by using coffee grounds comes from using too much and too many times.

The main advantage of coffee grounds materializes only when it affects the soil and changes its pH level. Also, you must get a soil test done to find the level of acidity in the soil.

  • Applying too much will make the soil acidic, so you need to use the right amount. Avoid using more than 1-2 cups of coffee grounds per rose plant.
  • Applying too often can result in mold formation. Coffee grounds need time to be worked into the soil properly. Overuse can cause more harm than any benefit.

Apart from this, there are some claims made against the use of coffee grounds on rose plants. In my opinion, they don’t hold true, but let us look at them and assess each point.

High Acidity In The Soil

Some people claim that coffee grounds can change the soil pH and acidify the soil. However, it is not entirely true because coffee grounds are not highly acidic.

Depending on the type of bean, they range from neutral to slightly acidic in nature. It is not enough to change the pH of soil unless it is already acidic.

High Nitrogen Levels Are Not Good

If the nitrogen levels are too high, it can stunt the growth of flowers. Coffee grounds do not have very high levels of nitrogen.

They contain 1-2 % nitrogen and 0.3 % each of potassium and phosphorus along with several micronutrients. Many synthetic fertilizers have much more nitrogen.

The carbon-Nitrogen ratio is close to perfect for a compost heap. Nitrogen in coffee grounds is quite safe for the rose bushes.

Caffeine Kills Plants

Caffeine is produced by coffee, tea, and some other plants. It is a natural insecticide. Some tests have shown that caffeine can stunt the growth of bacteria, fungi, plants, and seedlings.

Most of these studies use high doses of caffeine, and it is not the same when you use coffee grounds in your garden. Coffee grounds can affect seedlings, but the effects are short term.

Kills Earthworms

People use coffee grounds in vermin-composting to improve its quality. The key here is to not add too much and not make it the only food source.

When you add the grounds to the soil, you should keep an eye on the soil and the earthworms. If you notice that it is affecting the earthworms, then stop. However, with the right amount, there will hardly be any adverse effects.

Kills Microbes in The Soil

Caffeine and other chemicals that you add to the soil have antibacterial properties. It will have some effect on the microbes.

Coffee grounds are in a diluted form in the soil and have only a small effect. Most plants produce anti-microbial chemicals.

Even if coffee grounds kill some microbes, they also feed the microbes. Unless vast quantities of grounds are used, it is not a problem.

Points To Remember

Though most people agree that using coffee grounds for rose plants is beneficial, there are still some divided opinions. Though most of the concerns are unfounded, if you plan to use coffee grounds, it is better to keep some points in mind.

  • Getting your soil tested is an excellent place to start, especially if there are many rose bushes.
  • Mulching with coffee grounds is not harmful, but it is advisable to keep it away from seedlings and new plants.
  • Applying at the right time, which is the start of the season, is important.
  • Avoid using it directly in large quantities. As we have mentioned earlier, too much and too often can damage the soil and plant.
  • The best way to use coffee grounds is by adding it to the compost heap. When it is mixed with other organic materials, it decomposes and becomes harmless to plants.


Roses need a little bit of care and effort from you to grow healthy and flower beautifully. Coffee grounds can help you by improving drainage around the plant.

It improves the soil condition to allow plants to thrive. However, you must take all the precautions such as the right quantity, right season, application method, etc. to ensure maximum benefit. Roses need nitrogen, which coffee ground can provide.

You should monitor the plant carefully, especially if you are trying this for the first time. You will be able to notice any adverse effects and can step in immediately.

We hope that you find the information we have shared useful. Please feel free to contact us for any queries or doubts. We will be happy to help you in the best way possible.

Adding coffee grounds at the right time can result in a colorful and fragrant garden that you can enjoy.