16 ways to use old coffee grounds

1. Fertilize Your Garden

Most soil does not contain the essential nutrients needed for optimal plant growth. Also, as plants grow, they absorb nutrients from the soil, ultimately leaving it depleted. Thus, most gardens need to be fertilized to ensure that plants have the nourishment they need to survive. Coffee grounds contain several key minerals for plant growth — nitrogen, calcium, potassium, iron, phosphorus, magnesium and chromium. They may also help absorb heavy metals that can contaminate soil. What’s more, coffee grounds help attract worms, which are great for your garden. To use coffee grounds as fertilizer, simply sprinkle them onto the soil surrounding your plants.


SUMMARY Coffee grounds make great fertilizer because they contain several key nutrients required for plant growth. They can also help attract worms and decrease the concentrations of heavy metals in the soil.


2. Compost It for Later

If you do not have an immediate need for fertilizer, you can compost your coffee grounds for later use. Composting is a natural process that turns organic items such as food scraps and yard debris into a dark, rich material called compost or humus. Adding compost to your yard or garden can help the soil hold onto more nutrients and water, thereby improving the health of your plants. One study found that compost made with coffee grounds and kitchen waste was richer in nutrients than compost made with waste alone. Another study compared four batches of compost containing 0, 10, 20 and 40% coffee grounds. The batch containing 40% coffee grounds produced the fewest greenhouse gas emissions and best quality compost. Other items to compost include grass clippings, leaves, bark, shredded newspaper, brush, herbs, egg shells, stale bread and fruit and vegetable trimmings. You should avoid composting meat and fish scraps, dairy products, diseased plants, grease and oils.


SUMMARY Adding compost to your garden can significantly improve the health of your plants. Coffee grounds can help increase nutrient levels and decrease the greenhouse gas emissions of your compost.


3. Repel Insects and Pests

Certain compounds found in coffee, such caffeine and diterpenes, can be highly toxic to insects. Because of this, you can use coffee grounds to repel bugs. They are effective at deterring mosquitos, fruit flies and beetles, and they may help keep other pests away too. To use coffee grounds as an insect and pest repellent, simply set out bowls of grounds or sprinkle them around outdoor seating areas. You can also keep pests out of your garden by scattering coffee grounds around your plants. They help create a barrier that slugs and snails do not like to crawl over.


SUMMARY Coffee grounds contain compounds that are toxic to many insects. You can use your coffee grounds to repel mosquitos, fruit flies, beetles and other pests.


4. Remove Fleas from Your Pet

Fleas are a common problem in household pets, and treating them can be costly and time-consuming. There are several flea-removal products on the market, but many contain harsh chemicals and can produce unwanted side effects. Luckily, fleas don’t seem to like coffee, and you may want to consider coffee grounds as a natural treatment. Simply rub the grounds throughout your pet’s fur after shampooing. Then rinse them off and allow your pet to dry as usual. Some say doing this may also add smoothness and shine to your pet’s coat, but there is little to no research to support either of these claims. However, coffee grounds may be less effective than a prescription product, so if your pet has fleas and this treatment does not work, you may want to contact a vet to discuss alternative options. Also, coffee grounds should only be used externally. They can be toxic to dogs if consumed.


SUMMARY Like other insects, fleas do not like coffee. Bathing your pet in used coffee grounds may help keep fleas at bay.


5. Neutralize Odors

Coffee grounds contain nitrogen, which helps eliminate a foul-smelling sulfur gas from the air when it’s combined with carbon. In other words, coffee grounds can help absorb and eliminate odors. You can place a bowl of coffee grounds in your fridge or freezer to neutralize odors from spoiled or fragrant foods. You can also fill old socks or pantyhose with coffee grounds and tie them off to make portable air fresheners. Place these in your shoes, gym bag, bedroom drawers, under your car seat or anywhere else that may need some deodorizing. You can even keep coffee grounds by the sink and use them to scrub your hands after chopping garlic or onions. The grounds will help remove the smell from your hands.


SUMMARY Coffee grounds can help absorb and eliminate odors from your refrigerator, gym bag or smelly shoes. Using them as a hand scrub can also help remove lingering smells from onion or garlic.


6. Use It as a Natural Cleaning Scrub

Coffee grounds are abrasive and can help remove buildup on hard-to-clean surfaces. They may even help sanitize due to their antibacterial and antiviral properties. If you like to avoid cleaning with chemicals, used coffee grounds might be worth a try. Use them to scour your sink, polish your cookware or clean your grill. Just be careful not to use them on any kind of porous material, as they can cause brown stains.