We recommend using about a teaspoon of coffee grounds per gallon of water. Let the coffee grounds and water mixture steep for a few nights, stirring occasionally, then strain the liquid through a cheesecloth. The remaining liquid can be used to water, and gently fertilize, your houseplants.
Coffee grounds are rich in nutrients, especially nitrogen. They also have some amount of other nutrients like potassium and phosphorous. Overall, this means that adding coffee grounds to your garden can work fairly well as a fertiliser. Coffee should be spread in a thin layer, rather than being clumped in one place.
In most cases, the grounds are too acidic to be used directly on soil, even for acid-loving plants like blueberries, azaleas and hollies. Coffee grounds inhibit the growth of some plants, including geranium, asparagus fern, Chinese mustard and Italian ryegrass.
Coffee grounds are highly acidic, they note, so they should be reserved for acid-loving plants like azaleas and blueberries. And if your soil is already high in nitrogen, the extra boost from coffee grounds could stunt the growth of fruits and flowers.
Fresh coffee grounds are acidic. Used coffee grounds are neutral. If you rinse your used coffee grounds, they will have a near neutral pH of 6.5 and will not affect the acid levels of the soil. To use coffee grounds as fertilizer, work the coffee grounds into the soil around your plants.
Not all plants love acidic soil. The best advice is to not overdose the garden with coffee grounds. You may like 3 cups a day, but your plants won't love that much coffee. Even the plants in this list won't love super acidic soil.
Since coffee grounds have such a pungent and intense smell, mosquitoes do not like to come near it. Mosquitoes are repulsed by all types of coffee, whether it is fresh, used, or burnt. The most effective way to use coffee grounds for mosquito control is by burning them, as it creates a stronger aroma.
Don't just pour it down the drain — you can use it to fertilize your plants, both indoor and outdoor. Coffee grounds (and brewed coffee) are a source of nitrogen for plants, producing healthy green growth and strong stems. Coffee also contains calcium and magnesium — both of which are beneficial to plant health.
Some experts suggest that you can sprinkle your coffee grounds in the soil next to the plant, but others warn that you should be careful not to put too much on as the high nitrogen content could actually burn – and kill – them. Do not use more than a cup for each bush.
'Coffee grounds are an excellent houseplant fertilizer due to their high nitrogen content (about 2 per cent) that releases slowly into the potting media as they decompose. However, coffee grounds have more to offer to plants than just nitrogen,' she says.
There are a select few plants that can benefit from fresh grounds—including acidity-loving Hydrangeas, Rhododendrons, Azaleas, Lily of the Valley, blueberries, carrots, and radishes—but generally, most common houseplants will prefer low to no acidity.
The shells also contain other minerals that help plants grow, including potassium, phosphorus, and magnesium. Eggshells are, therefore, an effective and inexpensive fertilizer for outdoor garden soil and houseplants.
Coffee grounds contain around 2% nitrogen as well as varying amounts of phosphorus and potassium which are all very important for the growth of tomato plants.
One study published in the Journal of Agricultural and Food Chemistry found that coffee grounds were more effective at repelling rodents than commercially available products. Coffee's bitter compounds are responsible for its repelling effects. These compounds make the coffee unpalatable to rats and mice.
These things are great for nutrient poor lawns and lawns on clay or sandy soil. However, coffee grounds still contain some residual caffeine, which can cause harm to the micro fauna in your soil, and that's why it is not recommended to apply coffee waste directly to your lawn.
Eggplant, peppers, broccoli, cauliflower and leafy greens, to name a few. But don't go overboard. Since it takes a while for the shells to decompose, Uyterhoeven recommends applying eggshell fertilizer to your garden or indoor plants just twice a year—in the fall and spring.
One final note: Make sure your soils aren't already alkaline before you add anything to up the pH; and never ever use eggshells or other pH-raisers around acid-loving plants like azaleas and rhododendrons.
Banana peels can be placed directly onto pot plant soil, or around the base of your garden as mulch. As they decompose, they will release nutrients into the soil to feed plants. If using banana peels in your garden, place a single layer straight on top of the soil, being sure not to let them touch the plant stem.
Plants that like coffee grounds also respond well to watering with coffee liquid. However, it is a fairly strong fertilizer, so this watering should not be done more than once a week.
Not only do they repel mosquitoes, but also other insects such as wasps and bees. Coffee grounds are the bee's knees when it comes to staying bug bite free. Most bugs have a very strong sense of smell. Coffee grounds are very potent and even more potent once they are burned.
Coffee beans, grounds and brewed coffee contain caffeine, a very dangerous and toxic chemical to cats and dogs. Ingestion can be life threatening. According to the Pet Poison Helpline, a moderate amount of coffee can easily cause death in small dogs or cats.
Mosquitoes hate the smell of lavender, citronella, clove, peppermint, basil, cedarwood, eucalyptus, peppermint, lemongrass and rosemary. They also hate smells such as smoke, for further insight, see our exploration on, does smoke keep mosquitoes away?
She recommends that grounds make up no more than 15 to 20% of the total compost volume. Because they are acidic, coffee grounds make good acid mulch. Of course, too much of anything is just too much, so apply coffee grounds in limited amounts.