If you aim for about 1/4 coffee and 3/4 water, or even a half-and-half mix, in your solution (depending on how strongly you brew your coffee), that's about right, but you don't have to be fussy about it. You can use coffee fertilizer on your potted plants, houseplants and in your vegetable garden.
The key to using used coffee grounds as a liquid fertilizer is dilution! Too much of a good thing is possible, particularly for plants potted in containers. We recommend using about a teaspoon of coffee grounds per gallon of water.
How Often Should You Add Coffee Grounds to Plants? You can fertilize houseplants an average of 7 to 10 days in a row, but no more, as there is a risk of over-acidification of the soil. A cup of ground coffee should be added to the compost once a week.
Compost Coffee Grounds.
Take care to add grounds so that they comprise only 10 to 20 percent of your total compost volume. Any higher, and they might inhibit good microbes from breaking down organic matter. Another way to approach this volume is to add 4 parts shredded leaves to 1 part coffee grounds (by weight).
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.
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.
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.
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.
The hot water can only absorb so much coffee, so overfilling with grounds only wastes coffee grounds (and money). The Solution: Measure out your grounds to get just what you need.
Compost coffee grounds for a vegetable garden instead of using them directly. Remember, coffee grounds are not good for tomatoes or seedlings. Get a soil test, especially if your plants are not thriving or you want to change the acidity of the soil.
Composting used coffee
Ensuring a balanced mix of 'wet' and 'dry' materials is the best way to achieve good compost. The nutrients contained in coffee grounds will be recycled back onto the soil when finished compost is used as a mulch or dug into the soil. Also add any un-drunk coffee to dry material in a compost bin.
You may love your morning coffee, but ants could do without it. Another natural way to deter ants, sprinkle coffee grounds outside and around your garden. The smell repels them and they'll be looking for a less caffeinated place to hang out. Want to keep your home clean and clear of ants?
Using Coffee Grounds as Fertilizer
To use coffee grounds as a fertilizer sprinkle them thinly onto your soil, or add them to your compost heap. Despite their color, for the purposes of composting they're a 'green', or nitrogen-rich organic material.
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.
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.
'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.
Don't Reuse Coffee Grounds. Overall, we don't normally recommend reusing coffee grounds to make another cup or pot of coffee as it dilutes the flavor and can make the coffee taste more bitter than what is intended.
If you don't use enough coffee, it will result in a weak, thin, flat, and watery cup. On the other hand, if you use too much of the good stuff, this will make the coffee feel muddy, heavy, and off-balance, without any real depth. You can experiment with the amounts but don't depart too far from the recommended ratio.
Coffee is affected by how quickly water can extract flavor compounds from your grounds and by the duration of the brewing. Coarser, larger coffee grounds have less surface area than those that are finely ground. They allow water to flow more freely and they do not give up their flavor as quickly.
Coffee grounds take three to four months or more to decompose, depending on the soil microbial activity and health. The more microbial activity of the soil, the more quickly coffee grounds decompose.
Coffee grounds repel pests. Most pests do not like the smell of coffee, so they will stay away- Fungus Gnat is no different. If your coffee grounds are not repelling them, you're not doing it right. One thing you would have to do is to avoid spreading the coffee grounds on the face of your potting soil.
After you enjoy your morning caffeine boost, store your coffee grounds in an airtight container in the refrigerator (room temperature will make them moldy) until you are ready to utilize them for any of these many thrifty uses.
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.
“the smell of the coffee repels snails, slugs and ants. You may also have success using coffee grounds to repel mammals, including cats, rabbits and deer.”
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.