How are coffee grounds good for roses? This black gold can be extremely beneficial for a roses’ health and growth. Find out how to use them effectively.
From a logical standpoint, it would seem that spent or used coffee grounds are the ideal organic material for your garden. In fact, a quick search on the Internet would certainly seem to back this reasoning up.
A large number of articles will point to these “facts”. Spent coffee grounds are as healthy and beneficial to your garden and plants as the coffee itself is for you.
However, with a little research, some of the content will seem contradictory.
One thing is true. Used coffee grounds are a good source of readily available organic material and nutrients for your garden.
Instead of feeding your nearest landfill your money would be better spent feeding your garden and plants. But many an avid gardener will state that its use should be moderated and done correctly.
So to the burning question: Do roses like coffee grounds?
Anyone who enjoys gardening will, no doubt, have the desire to add rose bushes to their yards. The color and fragrance offered by roses are undeniable.
The question is… what do rose bushes need for optimal growth, and can used coffee grounds help?
In a nutshell, rose bushes enjoy the following growing conditions:
It is widely understood that coffee contains acidic compounds. So their benefit to your rose bushes seems immediately apparent.
However, the majority of acidic compounds in coffee are water-soluble. This means that most of that acidity ends up in your morning coffee.
Used coffee grounds are largely pH neutral or only slightly acidic.
While these coffee leftovers decompose they will release any remaining acidity into the soil. But large quantities of grounds will be needed to lower the pH of soil.
Experienced gardeners will advise against the use of large amounts of spent coffee grounds. Therefore, don’t rely on your these solely to raise the acidity of your soil.
It is very true that used coffee is a source of fixed nitrogen. As the granules decompose some of this will be released into the surrounding soil or compost heap.
However, the grounds only contain 1-2% nitrogen which is far lower than synthetic fertilizers. They have a carbon to nitrogen ratio (C/N ratio) of 20:1. Thus making it an excellent material for your compost heap.
Other nutrients found in used grounds that will be good for the soil and your rose bushes are:
It is also true that spent coffee grounds help improve the soil tilth or structure by loosening it. This will help with root growth and the delivery of water and other nutrients.
This will also aid in the draining of excess water which rose bushes prefer.
A loose soil structure will also encourage earthworm activity and the thriving of other microbes.
If applied correctly and in moderation used coffee grounds can help to promote plant growth. So the logical answer to this question would be spring.
That would be September to November in the Southern Hemisphere and March to May in The Northern.
However, the experienced gardener may tell you that it is not quite as simple as this. Different plants have different growth cycles.
Rose bushes, for example, will go dormant for the winter months. So promoting growth at this time would be detrimental.
It has also been observed that using spent coffee granules on and around seedlings and young plants can inhibit or stunt growth. Therefore it is best used for plants that are already established.
If you have any questions as to when used grounds are best applied, it is a good idea to follow the advice given at your favorite gardening center regarding roses and coffee.
Many experienced gardeners will warn you that it is best to use spent coffee grounds in moderation. With good reason.
Being a tropical plant, the living coffee plant uses natural defense mechanisms against bacteria and insects. This happens in the form of chemical compounds with caffeine being the prime example.
These chemical defenses are also found in the coffee bean itself. Many of these find their way into the end product that you purchase.
However, the brewing process does not release all these chemical compounds. They remain “locked” in the grounds.
Only decomposition will help to release these compounds.
This decomposition process if old grounds from coffee are used in excess, can affect your garden negatively.
It is advisable not to use spent coffee grounds in large quantities anywhere in your garden. And none at all around seedlings and young plants.
It has also been observed that large quantities of used coffee dregs are not good for earthworms either. So moderation is again key if you want to use them for your compost heap.
Compost heaps are a mixture of “green” organic material and “brown” organic material. Despite its color, the brown grounds are considered green organic material.
Before adding them to your compost heap it must be mixed with brown organic material. This should include dried leaves and newspapers in a ratio of 1 to 4, 1 part green to 4 parts brown.
Once the grounds have completely decomposed they are safe to use anywhere in the garden.
It has also been observed that used grounds do not make for good mulching material. A good mulch must “breathe” and allow water to easily penetrate.
Coffee grounds have a tendency to compact and cake too easily. Therefore, using them as soil on their own is not a good option.
If they are to be used in mulch it is advisable to combine, in moderation, with other good mulching material.
Where To Source A Supply Of Used Coffee Grounds
If you are a regular coffee drinker then a ready source of used coffee grounds will always be available at home.
However, what about those who may not enjoy coffee? Or those who cannot afford coffee beans or commercially ground coffee beans?
What about those who enjoy their morning coffee, but cannot produce enough used coffee to meet the needs of their garden or compost heap?
Well, you will be happy to hear that with little to no effort you should have no problems sourcing enough to satisfy whatever gardening or composting needs you may have.
There are many places that would, most probably, be only too happy to give away leftover grounds for free:
Many coffee shops would be happy to part with their spent coffee. A quick discussion with management should provide you with a long-term supply.
Both of these sell large amounts of coffee to morning traffic. They would probably be overjoyed to give away their spent coffee grounds and paper filters.
They are additional examples where coffee is sold in quantity. A discussion with management should provide you with a good source of grounds.
Your place of work or the offices in which friends or colleagues work may very well have a central coffee maker. It would not take much effort to organize for office staff to set aside used coffee grounds every time they brew a fresh pot.
Don’t be afraid to experiment with the leftover coffee granules in your garden. Some plants have been observed to do well in soil augmented with used grounds, while others do not.
Examples of some plants that appear to get a boost are:
These plants are those that prefer more acidic soil chemistry.
So coffee grounds and roses are not the only pairing that will benefit each other
Don’t forget that if used grounds from coffee are properly composted, that compost can be used anywhere in the garden.
The more acid-loving vegetables such as carrots and radishes should receive a boost through the moderate use of used grounds. Again, experimentation will go a long way to helping you determine which of your vegetables benefit and which do not.
Properly composted coffee grounds should provide a boost to any vegetables you enjoy growing.
Are coffee grounds good for rose bushes?
It is true that used coffee does contain chemical compounds that will inhibit growth, especially in seedlings and young plants. However, large quantities of grounds are necessary before this becomes a concern.
Many an experienced gardener will tell you that moderation is key with roses and coffee grounds. One cup of grounds or so each week or every other week directly added to the soil, as fertilizer for roses, is sufficient in many cases.
If you decide to compost your old grounds before use in the garden remember that grounds are considered green organic material.
They must be added to your compost heap with brown organic material. Use dried leaves and/or newspapers in a ratio of 1 to 4 respectively.
So fertilizing roses with coffee grounds is indeed a good thing – done correctly.
When making homemade fertilizer, mix 1/2 a pound of used coffee grounds to 5 gallons of water. This mixture can be used twice a month on your rose bushes.
Used coffee grounds can be acidic and makes a good acid-based mulch. But use the grounds sparingly when making compost, everything in moderation. Use sparingly in your garden when adding to the soil unless you are feeding acid-loving plants like azaleas and camellias.
You can use grounds on your potted plants, vegetable garden, garden, and houseplants. Coffee grounds are a good source of nitrogen which promotes strong stem growth as well as healthy green growth in plants.
Anywhere near you that sells coffee! Try your local cafe, coffee shop or restaurant, fuel station or convenience store as well as you or your friend's office. There are always used grounds that are thrown away daily.
Acid-loving plants appreciate what coffee grounds add to your soil. These plants include azaleas, lily of the valley, rhododendrons, radishes, and carrots. Just keep them away from tomatoes, they do not like coffee and will not do well if exposed to it.