Coffee Grounds in Garden: Good Idea or Not?

fresh coffee grounds

Coffee is a very popular beverage consumed all over the world. Usually, you would discard your coffee grounds after you are done brewing your coffee but you might want to read this article first. April 22nd is considered earth day and thus the month of April is considered to be earth month, but why should you wait for one lousy month to recycle anything?

Coffee grounds have many uses around the home and garden and even in your beauty routine so you see maybe you can put some of those uses to use around your garden this year and in the process make a small difference to the health of the earth. The easiest way to get grounds is to make coffee, but don’t worry if you don’t make a lot of coffee at home, you can always get used grounds, for free, from your local coffee shops.

Now you might be wondering what exactly you would use used coffee grounds for in your garden. Don’t worry I’m here to answer some of your questions and put the uses of coffee grounds into perspective. I will also give you some tips on how to use coffee grounds around your garden this year, one way or another.

There are times when adding coffee grounds to your garden might be a bad idea, but don’t stress we will get to it all. Read on for all your coffee ground tips for the garden. You might have never known that you need grounds for gardening.

Compositing Coffee Grounds

Freshly brewed coffee grounds in paper coffee filters

Composting with used coffee grounds is a great way to reduce the amount of waste that is sent to landfills daily. Used Coffee grounds contain loads of nitrogen and thus are a great way to add some nitrogen to your compost bin or pile. Using them for compost is as easy as adding coffee grounds to your in your compost bin or pile.

Used paper coffee filters can also be used as compost to balance out the coffee. The paper coffee filters will break down since they are made of organic material adding to the brown material of your compost pile. Keep in mind that coffee grounds are considered green compost material and will have to be balanced with some brown compost material.

Brown vs Green Compost Material

Brown compost material is usually brown in color as the name states. Brown compost material usually consists of dried leaves, woody plants, wood chips, sawdust, corn stalks and newspaper. Brown material usually helps to add bulk and allows airflow through your compost pile and is a good source of carbon. Just put any dried leaves or old dead branches on your compost bin or pile to add some bulk and to create a well-ventilated environment for microbe growth.

Green compost material isn’t always green in color despite the name. Coffee grounds aren’t green, but they are considered green compost material due to their high nitrogen content. Green materials consist mostly of wet or recently growing materials for example grass clippings, food scraps, manure, recently trimmed plant leaves, recently pulled weeds and coffee grounds.

Most of the nutrients that make compost good for your garden comes from the green materials. Remember that you have to balance green compost material with brown compost material to create an environment good enough for microbes to release the nutrients your plants require from compost.

Using Coffee Grounds in Worm Bins

If you do vermicomposting with a worm bin, it is a great idea to add coffee grounds as worm food. Worms are crazy about grounds, especially earthworms. You can add on the grounds along with your other food scraps and discarded leaves from the garden in your worm bin to keep your worms with a coffee addiction happy.

The worms will consume the coffee grounds and turn them into worm castings which can be taken from the worm bin and used as a kind of compost for plants, the worm castings will also help to improve garden soil structure and quality. Make sure not to add too many grounds at once, the acidity may bother your worms which may lead to worm deaths. It is best to add 1 cup of coffee grounds per week for a small worm bin.

You may also be able to attract worms to your garden by using coffee grounds as a fertilizer. To do this, you can add the grounds directly into the soil around your plants. Do make sure that your plants will tolerate the acidity and caffeine before you decide on adding coffee grounds to your garden.

When deciding if used or fresh coffee grounds are better, take the following into account: Fresh coffee grounds retain all their caffeine and acidity since it has not been leached out by the brewing process. Used coffee grounds contain less caffeine and are almost neutral so may not affect your plants as much as putting fresh grounds in your garden.

Using Coffee Grounds as Fertilizer

coffee ground as fertilizer

Some acid-loving plants really appreciate acidic soil and coffee grounds are often used to make the soil more acidic. Unfortunately, not many people know that used grounds are closer to neutral so you cannot rely on only brewed coffee grounds to drastically change the pH of your garden soil. Fresh coffee grounds are often much more effective at dropping soil pH since they are more acidic before brewing.

To drop your soil pH effectively, take fresh coffee grounds and work them into the soil, they also function quite well as a slow-release fertilizer, around your acid-loving plants. You can also use leftover diluted coffee to water your acid-loving plants. Doing so will have the same effect as adding fresh coffee grounds directly into the soil.

Certain plants appreciate the acidity of coffee grounds more than others. Garden plants that would appreciate fresh grounds around them are plants like hydrangeas, azaleas, rhododendrons, blueberries, carrots, and radishes. Coffee grounds also have some other benefits.

Coffee grounds also contain other essential nutrients that gardens need like nitrogen, calcium, potassium, iron, phosphorus, magnesium and chromium which makes them a good slow-release fertilizer when put into your compost pile or garden soil. As plants grow they absorb nutrients such as nitrogen ultimately making the soil nitrogen-poor and unsuitable for sustaining plant life. Coffee grounds can be used to replace nitrogen and other essential nutrients, just think of how much your garden plants will thrive with a little nitrogen boost.

Unlike compost, placing coffee grounds straight into the soil will not immediately add nitrogen to your garden. The biggest benefit of adding coffee grounds directly into the soil of your garden is that grounds add organic material, which biggest use is to improve water drainage, water retention and aeration of the soil.

Coffee Grounds as Natural Pesticide

Snails, slugs and other garden pests are said to detest coffee grounds, but the rough surface of the grounds also work against them even if the caffeine content is low. You can use grounds to create a barrier against slugs and snails by placing the grounds around plants whose leaves are prone to be damaged by these creatures.

The grounds are effective because they are naturally abrasive and sharp and it contains caffeine as a deterrent. When slugs or snails move over the barrier, their bodies are cut and damaged by the coffee grounds or they get deterred before even reaching the barrier, by the caffeine it contains.

Coffee grounds may be your perfect organic solution to use against pests in your garden but don’t only rely on its repelling effect alone. Some studies have shown that sometimes grounds have no effect whatsoever on slugs and snails. The reason, even though they are repelled by caffeine, is that used coffee grounds have such a low amount of caffeine left and become so soft that there is almost no effect which makes them no help at all.

Coffee grounds, especially the fresh ones, are quite acidic and thus should not be used close to plants that do not prefer acidic soil. Using grounds as an organic pesticide may not be effective in this regard and you may accidentally kill your plant instead. Coffee grounds should never be used around plants like tomatoes who prefer more alkaline soil.

For the best results as a pest repellent in your garden, I would suggest the use of fresh coffee grounds instead of the brewed kind. No matter what you decide, always make sure to only use coffee grounds away from plant stems.

Coffee Grounds as a Pet Repellent

Coffee grounds work as an excellent pet repellent, at least for those who own a cat. Anyone with a cat or dog will know how much effort it can be to stop your beloved pet from digging up your garden plants. Most people are against the idea of putting up fences in their gardens to keep their pets out and have soughed another solution.

Adding coffee grounds to your garden will stop your beloved cat from using it as a litter box and potentially digging up your plants and seedlings. Don’t have any coffee grounds available? It is quite easy to get some all you have to do is use some fresh coffee grounds, if you want the acidity as well, or make coffee and use your leftover grounds.

Unfortunately, Coffee grounds are not the best option if you have a dog. Everyone who owns a dog will know that caffeine is particularly harmful to dogs. Even though used coffee grounds have particularly low caffeine content, it is probably best not to never expose your dog to any of it at all.

If you own a dog, I suggest to rather keep your garden caffeine-free for your dog’s sake. Take some time to think about it before you disregard the idea completely though. You could still potentially use coffee grounds in your garden if you are willing to keep your dog out of it with some kind of barrier.

Coffee Grounds as Mulch

Coffee in garden with mulchMulch can be expensive to buy because you need so much of it to cover your garden properly. Many families brew a lot of coffee and thus the suggestion to use coffee grounds in the garden instead of the original mulch has come up. It is possible to use coffee grounds as mulch, simply spread the grounds in the garden and use leaves, compost, or coarse organic material such as wood chips or bark (that is cheap and easily available in bulk) to cover them.

Take note that for coffee grounds to work as mulch, you can’t spread the coffee grounds on too thick. Ideally, the mulch should be half an inch thick at best, less is even better. Make sure to keep it away from the plant stems.

Those who fail with this type of mulch are those who tend to heap it on too thick. When the much is too thick, the ground will become compacted and offers an opportunity for mold growth by preventing water from freely draining.

Coffee grounds also contain caffeine that inhibits plant growth. For this reason, if you put coffee grounds around seedlings or over seeds, the caffeine might inhibit growth and germination. It is best to keep coffee grounds away from seedbeds and seedlings at least until the plants are grown to an appropriate size.

Some plants are more sensitive to caffeine than others. Some plants may need the acidity from the coffee ground mulch to grow properly, but others may shrivel and die when exposed to the caffeine. It is best to put some effort into research before you use coffee grounds everywhere in your garden.

You might also want to experiment with coffee mulch on a small patch before it takes over your usual gardening practices. Keep in mind that coffee grounds cause slow plant growth in some plants such as broccoli, leek, radish, viola, and sunflower.

Use coffee grounds with other organic material to prevent compacting your soil. Coffee grounds, on their own, make a terrible mulch the ground compact way too fast. For mulch to be effective, it needs to let air and water in and out of the soil.

Mulch that compact have an effect on the ecology of your garden. When the mulch compacts too quickly, earthworms have trouble navigating through it and may get stuck and die. For this reason, coffee ground mulch is one of the leading causes of worms dying in gardens.

Reasons Why You Should Be Using Coffee Grounds

Coffee ground decreases weed growth

Coffee grounds contain caffeine and caffeine sometimes has an effect on plant growth and germination. Some weeds are sensitive to it and will fail to outgrow your plants that love coffee. There is, however, no guarantee that it will work perfectly since some weeds may like coffee as well.

Coffee grounds hold water quite well.

Coffee grounds are excellent for water retention. They absorb water quite well which is great if you want a well-draining but moist soil.

Coffee grounds repel cats from your garden

Cats hate the smell of coffee and are repelled by the caffeine. A cat will rather move on to another garden or a litter box before littering further in your garden.

You can decrease soil pH with fresh coffee grounds

Fresh coffee grounds are quite acidic since the acidity has not yet been extracted by the brewing process. This makes them perfect for dropping soil pH.

Coffee grounds are an excellent source of nitrogen and other essential nutrients

Coffee grounds contain essential nutrients that gardens need like nitrogen, calcium, potassium, iron, phosphorus, magnesium and chromium. They can be used as a slow-release fertilizer or added to a compost pile.

Coffee grounds may be able to repel snails and slugs

Coffee grounds are sharp and contain caffeine. When slugs and snails move over a coffee barrier, their soft bodies get damaged by the sharp edges. Some slugs and snails will be repelled even before they reach the barrier.

It is an organic fertilizer

Coffee grounds can be used as a slow-release fertilizer as mentioned above.

Excellent additive to compost bins or compost piles.

Coffee grounds contain a heap of essential nutrients like nitrogen which will add to your compost pile

Excellent for worm bins

Worms are coffee addicts and will turn it into a substance that plants can readily use.

Great for luring earthworms to your garden

Earthworms are also coffee addicts and will readily come to your garden when it is available to them.

Easy and cheap to come by

Coffee grounds are easy to come by. you can get used grounds for free from local coffee shops or you can use your own leftovers after your morning drink.

Reasons Why You Shouldn’t Be Using Coffee Grounds

Coffee grounds may inhibit plant growth

Putting coffee grounds directly into the garden can lead to an excess of caffeine and inhibit plant growth and the germination of seeds.

Some plants prefer more alkaline soil

Not all plants prefer the same growing conditions, read up on what your plants prefer before adding grounds to your garden. If you don’t do the proper research, your gardening efforts might prove pointless.

Coffee grounds compact to fast to be a great mulch

It is true that grounds compact quite quickly. If you want to use it as a mulch, make sure the layer is thin and mix it with other brown compost material.

A lot of acidity is lost when brewing coffee grounds making them ineffective to change soil pH

FAQ

Which plants like used coffee grounds?

Before using coffee grounds in the garden, it is best to think of which plants will actually thrive in the presence of grounds. Plants like hydrangeas, azaleas, rhododendrons, blueberries, carrots, and radishes would appreciate some coffee grounds in the garden around them.

Which plants do not like coffee grounds?

Some plants would rather prefer coffee-free garden soil. Plants like tomatoes, broccoli, leek, radish, viola, and sunflower do rather poorly with coffee grounds in the garden soil regardless of how much fertilizer is added as well.

Are coffee grounds good for the garden?

Depending on the type of plants you have in your garden, coffee grounds may be either good or bad. Do some research before gardening with coffee grounds. Coffee grounds inhibit the growth of some plants due to the caffeine they contain. Some plants also don’t like the extra acidity that grounds tend to add to the soil.

Are used coffee grounds good for tomato plants?

Tomato plants do quite well with used coffee grounds, especially if the grounds are mixed into compost or other organic matter. Used coffee grounds have lost most of their acidity and caffeine which lessens the effect on plants. They are an excellent source of nitrogen so your tomato plants will appreciate a bit of coffee grounds in their soil.

So, is having coffee grounds in garden a good idea?

Freshly brewed coffee grounds

If you decide to put coffee grounds in your garden you can have one of two results. It can either work brilliantly for you and become your go-to method year after year, or you can suffer a great loss. The use of coffee grounds in the garden has become very popular as of late. Many decided to use coffee grounds because it is a cheaper option than normal mulch. You can also add coffee grounds to your garden in many different ways. One of these ways is to add it to your compost pile.

So as a final verdict, I would suggest doing the research before using coffee grounds for anything. As you can see, coffee grounds do not work for all types of plants and it is best to keep them far away from those plants. Other plants may like the coffee grounds around. It is always best, however, to keep coffee grounds away from seedbeds and seedlings.

After doing the research, experiment on a small patch in your garden and see what happens. If you see that your experimental plant thrive then by all means add coffee grounds to your garden. If you find that your plant is doing much more poorly and than its coffee free brethren, then I suggest that you think twice before introducing coffee grounds.

Also, keep in mind that coffee grounds are terrible for dogs, so you might have to reconsider before using them as a pet repellent. They do, however, work great for keeping cats out of the garden.

Go do some more reading, a few experiments and have some fun finding ways to use coffee grounds in your home and garden.


For more reading:

Exit mobile version