Many gardeners are discovering the benefits of adding used coffee grounds, the leftovers of your morning cup of java, to their garden.
Used coffee grounds can provide your garden with higher nitrogen levels, making it great for plants that require acidic, low pH soil. It can also prevent snails and slugs, and keep cats from using your garden as their restroom.
In this article, we’ll discuss how to use coffee grounds for your plants and discuss the benefits you can get from recycling waste material into a natural plant supplement.
Are coffee grounds good for your garden?
Used coffee grounds are a waste material, meaning many people toss it away after brewing their coffee. But more commonly, people are starting to recycle their used coffee grounds by adding the leftovers to their gardens.
This might sound like a weird idea, but there are many benefits to adding coffee grounds to your plants. Coffee grounds can help produce nitrogen in the soil, although the acidity level can vary by type of coffee.
Recycled coffee grounds can also prevent pests like snails, slugs, and cats from getting into your garden. Putting coffee grounds around your plants can also improve the way the soil drains and collects air. There are different ways you can use coffee grounds in the garden.
Coffee Grounds as Compost
As the material breaks down, it produces nutrients that have many advantages for your plants. Composting is cheaper than store-bought fertilizer, and it helps reduce the amount of waste that ends up in landfills.
You add this compost to your garden to help provide nutrients to your soil. If you need higher nitrogen, compost is the way to go. However, not all plants will like the nutrition that comes from compost.
Coffee grounds are a green compost material. For your compost to provide nutrition for your plants, you need a balanced mix of green and brown compost.
Green compost means wet or recently grown materials. Most of the time (but not always), green compost has a green color. Green compost breaks down and creates nitrogen, which is why it’s suitable for your garden.
Types of green compost include grass clippings, food scraps, manure, freshly pulled weeds, coffee grounds, and paper coffee filters.
Brown compost is dry or woody plant materials such as wood chips, straw, dry leaves, sawdust, paper, and corn stalks. Your compost needs brown items for it to break down properly. Brown compost creates carbon nutrients, which work with the nitrogen.
Your compost should have a mixture of 4:1 brown to green compost. When your compost doesn’t have enough nitrogen, it won’t warm up enough to start the decomposition process. You can end up with a smelly pile of decaying junk.
If your compost pile isn’t breaking down, try adding more green compost to the pile. If your compost is starting to stink, you can fix it by adding additional brown compost.
Coffee Grounds as Fertilizer
Another way that many people use coffee grounds for their gardens is as a fertilizer. Coffee grounds contain a lot of nitrogen, but they also have low potassium and phosphorus traces, which are great for your plants.
However, adding used coffee grounds directly to the soil will not immediately change the pH levels. The used ground has a neutral pH. If you need more nitrogen in your soil, you will do better adding coffee grounds to compost and adding that to your soil.
Fresh coffee grounds, which are acidic, can change the pH level if you don’t mind wasting good coffee for your plants. You can also pour the remnants of your coffee from your cup into your plant for a boost of fertilization.
A light sprinkling of grounds around your plants can improve water retention, drainage, and aeration (air circulation). However, be sure you don’t add vast clumps of grounds. It needs to be a thin layer.
Many people prefer to mix the coffee grounds into the top of the soil so the coffee can’t clump together. Because coffee binds together, it can cause a barrier over your soil, preventing any water from getting beneath the surface.
Coffee Grounds as a Pesticide
Not only are coffee grounds good for changing the soil’s nutritional contents, but they can also help prevent unwanted pests.
If you have a frequent problem with slugs or snails, mixing coffee grounds into the soil will prevent the problem. Coffee contains caffeine, which is harmful to these nuisances, so they avoid your garden.
And in some cases, coffee grounds have deterred cats from using gardens as their litter box. But this isn’t always the case, so be watchful during weeding, so you don’t end up with an unwanted surprise in your hand.
Coffee grounds seem to be a natural attractant for earthworms, which provide many benefits to your garden. Adding used coffee grounds to your compost will attract worms, which will help the compost break down faster and richer.
Here’s a video for more information on using coffee grounds in your garden.
Which plants like used coffee grounds?
Any plant that prefers a nitrogen-rich soil can benefit from having the additional nitrogen from the coffee ground. Use coffee grain on plants that flower, as they may grow large, but they can produce less full flowers.
Before using coffee ground on your flowers, determine what pH level your plants need. You’ll want to limit coffee grounds gardening to plants that require a lower pH, meaning the soil is more acidic. A pH of 5.5 is a good level to strive towards for your acid-loving plants.
Types of plants that you can add coffee grounds to include:
- Japanese iris
- Dogwood trees
- Beech trees
- Pin oak trees
- Any root plant like radishes or carrots
Are coffee grounds good for a vegetable garden?
Adding coffee grounds to your vegetable garden can increase the levels of potassium, copper, magnesium, and phosphorus in the soil. It also allows nitrogen to release into the ground over an extended period slowly.
However, using too many coffee grounds can damage your plants, so you want to be careful. The best way to use coffee grounds for your vegetable plants is to add them to compost.
You can also apply coffee grounds directly to the soil around your plants. The layer should not exceed one inch of ground or a 35% ratio to 65% soil.
Cover the grounds with bark mulch, leaves, or compost. Then till the soil at a depth of six to eight inches to work the coffee into the dirt.
Are coffee grounds good for tomato plants?
Plants like tomatoes can benefit from using coffee grounds. The little nitrogen of the grounds can give your plant a boost of nutrients.
And coffee grounds can keep common pests off your tomato plants. Your tomatoes will benefit more from compost than straight grounds if you need to alter the nutritional contents of the soil quickly.
If you want to add used coffee grounds directly to your plants, sprinkle a half-inch layer around the base of your tomato plants. Always cover the grounds with mulch, dried leaves, or compost so the grounds can break down quicker.
Avoid adding a thick layer of grounds, which could cause your plants to lose air circulation, as the fine texture of coffee grounds makes it easy for them to compact together, creating a barrier.
How to use coffee grounds for tomatoes
You can also use one cup of used coffee grounds to spread around the base of your plant. You would then need to use a small rake or shovel to work the grounds into the soil, at least two to three inches deep.
Some gardeners use well-composed coffee grounds right from the start. Adding a small amount of compost made with coffee grounds to the hole before transplanting seedlings can improve the soil composition and give your plants a slow, extended-release of nutrients.
Using composted coffee grounds as mulch in the summer helps your tomato plants retain moisture, get nutrients, and prevents weed growth.
Coffee grounds contain allelopathic properties, which means they prevent some plants from growing. Grounds can also avoid some fungal growth.
Can you put too much coffee grounds in your garden?
It is possible to add too much coffee grounds to your garden. Coffee grounds are small particles that can clump together, forming a thick paste.
When coffee binds together around your plants, it can cause a barrier that prevents water and air from getting down into the roots. This issue can cause your plants to become malnutrition or dehydrated, leading to severe damage or death.
Are coffee grounds good for grass and lawns?
Grass can benefit from fertilization by used coffee grounds due to the nitrogen, phosphorus, and other trace minerals that are in the grounds.
Coffee grounds break down slower, so your plants get extended nutrients without much effort from you once you’ve laid the fertilizer. Synthetic fertilizers such as those bought at the store break down faster, so your plants get the nutrients immediately but don’t have much for later.
And because worms love coffee grounds, your soil will benefit from microbial activity when the castings (poop) from the worms aerate your grass. Aerate means to have tiny holes in the soil, which allows water, air, and nutrients to reach the plant roots.
When the soil is compact and tight, roots can have a more challenging time growing deep. Shallow roots mean the grass is easy to pull up or damage. Aerating your soil is the best way to ensure your roots have plenty of room to grow.
So Are Coffee Grounds Good For Your Garden?
Adding used coffee grounds to your garden can provide multiple benefits for your plants. You will see better success adding your grounds to a compost pile and using that to fertilize your plants. But you can also add used grounds directly to the soil to provide extra nutrients, prevent pests, and provide better soil quality.