Coffee is a magical treat. Brewed into a hot cup, it can wake you up in the morning and help you feel ready for anything the day has in store. But did you know you can reuse the coffee grounds in garden fertilizer that you normally throw into the trash each day?
We have everything you need to know to get started using grounds in your garden. Learn exactly what coffee grounds do for soil health, which of your plants will benefit from coffee grounds the most, and how you can start reusing your java waste to help your plants thrive today.
What Can Coffee Do for My Garden?
Not only does reusing your coffee grounds allow you to save some landfill space, it makes something old come alive again with a new purpose. By taking your coffee grounds to the garden, you can create your own fertilizer.
Coffee grounds can make gardens thrive, especially for naturally acid-loving plants that need nitrogen and potassium. Low-nutrient gardens can benefit from adding the grounds to your soil, and there are a number of other ways you can use coffee grounds around your garden to make your garden thrive.
How You Can Use Coffee Grounds
There are a number of easy ways to use coffee grounds, from composting to adding the grounds directly to your soil. You can use the grounds once in a while, or add it to your plants as your re-pot during growing season. Just sprinkle grounds or some leftover coffee on your plants, or save them for a future date.
Composting
One of the easiest ways to use coffee grounds in the garden is to add the waste to a compost pile. Whether you already keep a heap or are new to the world of composting entirely, it’s an easy way to add some nitrogen to your pile. You can even compost the filters!
If you do already keep a compost pile, there are a few quick things you should know about composting coffee. First, coffee grounds are considered a green compost material, so they’re full of nitrogen. This means you’ll need to balance them with a brown (carbon) compost material.
Fertilizer
When using coffee grounds as a fertilizer, you can often place the grounds directly onto the soil. Although they add nitrogen to compost piles, your plants and soil won’t necessarily benefit from added nitrogen. They will, however, help your plants in numerous other ways.
The Main Benefits of Using Coffee Grounds As Fertilizer
All plants need nitrogen to remain healthy, and coffee grounds can help to create bushier and healthier-looking plants. When using coffee grounds as fertilizer, you can reap in the following primary benefits:
- Adds Organic Material to the Soil – This helps improve water retention and drainage, as well as soil aeration.
- Alters pH Levels – Some plants love acid and use higher pH levels to thrive, which fresh coffee grounds are perfect for.
- Keeps Wild Animals Away – The coffee’s caffeine is said to negatively affect pests like slugs, snails, ants, and rabbits, keeping them away from your plants.
- Repels Cats – If you have a neighborhood cat who has turned your flower or vegetable bed into a litter box, coffee grounds can help encourage them to do their business elsewhere.
- Helps Nitrogen-Deficient Plants – If your soil is low in organic content or has a nitrogen deficiency, coffee can improve the nutrients absorbed by your plant’s roots.
- Creates a Slow-Release Fertilizer – With nutrients like nitrogen, potassium, phosphorus, and other micronutrients in coffee grounds, your plants will receive a boost.
What Type of Coffee Works Best for My Plants?
Coffee is perfect for both indoor and outdoor plants. Depending on the acidity level each type of plant needs, you may see plants’ health improve quite quickly. The type of coffee you use, however, may not make much of a difference. What really matters is whether the grounds are used or dry, and whether the coffee is caffeinated or not.
Since fresh coffee grounds are acidic until they are brewed, used coffee grounds are ideal for most plants. Rinsed or used grounds have a neutral pH of 6.5, which won’t change the acid levels in the soil, nor harm your garden.
On the other hand, some plants love acid, especially indoor flowering houseplants. These plants can actually be watered once in a while using brewed coffee (minus the sugar, milk, or creamer) instead of water. They especially enjoy fresh coffee grounds in garden fertilizer. Coffee-loving plants include the following:
- Azaleas
- African violets
- Aloe Veras
- Amaryllis
- Begonias
- Bromeliads
- Cyclamens
- Ferns
- Gardenias
- Gladioli
- Hyacinths
- Hydrangeas
- Impatiens
- Lilies of the Valley
- Phalaenopsis orchids
- Roses
How Much Is Too Much Coffee?
What constitutes too much coffee may depend on the plant variety itself, and the type of coffee you use. Plants with lower acid tolerances may benefit from decaffeinated coffee, or by applying the grounds only once in a while to avoid complications.
If you’re not sure what acid level your plant likes, look for yellowing leaves. Too much acid in the soil will lead to sick or dead plants, and yellowing leaves are often the first sign that there’s too much acid in the soil.
When trying to use coffee irrigation, abandon the process and re-pot your plants if you see any warning signs. Also, remember not to use coffee with every watering.
It’s important to play around with coffee grounds in your garden. The best way to know if they will help your plants in the ways you’re hoping is to test out different methods and track the results in your garden journal. Experiment with your garden to find what works best for you.
Where You Can Find Coffee Grounds
You don’t need to spend money to take advantage of coffee in your garden. Even if you don’t enjoy drinking coffee yourself, you can find used grounds for free from your local coffee shops. Many shops consider the grounds a waste product anyway, so they give them away free of charge to gardeners who for them.
Starbucks is a great place to head for composting materials, or if you’re tracking down used grounds and don’t drink enough yourself to cover your needs. Most branches will be happy to set the grounds aside for you or hand them over if you show up at the end of the day.
Take a dry, clean bucket or bag with you to carry them home. Store them in a heap or composting bin, or use them in your garden immediately.
Basic Steps to Use Coffee Grounds in the Garden
If you have an acid-loving plant, you can spread some coffee grounds directly onto the soil. No need to rinse the grounds of even use them first. That said, if you plan to use your old coffee grounds, there are a few more easy steps to the process.
Steps to Using Old Coffee Grounds in Fertilizer
- Rinse your used coffee grounds with cold water if you have lower acidity-loving plants.
- Sprinkle a thin amount of coffee grounds onto the top layer of the soil or within the top two inches of soil. If you have a vegetable garden, spread a 1-inch layer of moist coffee grounds in the soil.
- Use a nitrogen fertilizer (following the package directions) to speed up the decomposition of the grounds and add more nutrients to vegetables or plants.
Make a Tea
You may also be able to create a “coffee ground tea” using a ratio of two cups of used coffee grounds with five gallons of water. Allow the mixture to steep overnight, place the concoction in a spray bottle, and you have your very own liquid fertilizer. Spray this directly onto your plants’ leaves and stems for an added boost.
Repotting Season
If you’re repotting a houseplant to planting new vegetables, you can also sprinkle the coffee grounds into the potting soil as you plant. Simply mix the grounds in with the fresh soil in your pot. If you’re using coffee grounds in a flower bed, on the other hand, add a handful of grounds to the top of your soil no more than a half-inch thick, and use a fork or small rake to spread the coffee evenly in the flowerbed.
Alternatively, some people prefer to mix the topsoil and Java together in a wheelbarrow. Then, they walk around the back around shoveling out the mixture as needed.
Composting
You can also add your coffee grounds to your compost pile. Just balance the addition with a 4-to-1 ratio of brown compost material such as dry leaves or newspaper clippings.
For an added boost, try mixing the leftover grounds with eggshells to make your own rich fertilizer.
What Type of Garden Thrives Best with Coffee Grounds?
If you’re growing tomatoes, you may avoid adding coffee grounds in the garden. Slightly acidic soil works great, but tomatoes generally don’t fare well with high acidity levels. That doesn’t mean you shouldn’t work in a small number of coffee grounds in vegetable gardens with tomatoes. They can actually help suppress weeds and keep pests at bay.
Root crops will respond well to higher acidity, especially if you add the coffee grounds to the soil as you’re planting the seeds. The following types of fruits and vegetables respond well to added coffee’ acidity:
- Blueberries
- Strawberries
- Radishes
- Carrots
- Ginger
- Onions
- Turnips
- Parsnips
- Beets
- Yams
Best of luck to you!
