Usually the word "Free" is quick to gain your attention and in this day and age is often hard to find. When it comes to our gardens anything that we can get for free is a great find. One such item is a free fertilizer that is a byproduct of one of the most popular drinks in the world. That's right. I am talking about coffee. More specifically I am talking about the byproduct of making coffee which are the coffee grounds themselves.
Where to Get Them
Do you or someone you know have a caffeine/coffee problem? Although I am not a coffee drinker I do work in a corporate type office in which there are multiple pots of coffee being brewed at any given point throughout the work day. For the most part these grounds are usually thrown away or washed down the sink as they are considered a waste product. One statistic states that Starbucks alone, in the USA apparently produced coffee waste to the equivalent to the weight of 4 x 747 planes in just one year. This means that these grounds can usually be found for free. In my office I am usually able to fill a 1 gallon milk jug every day with used grounds. That quickly adds up. If you are not located in an office environment you may want to check with your local coffee shop. Often times these shops have green initiatives in which they set aside or package the grounds for local gardeners. Usually the grounds or free or for a small fee that is usually donated to some kind of charity. If you don't see them being offered in your local coffee shop then just ask the friendly barista. Being a regular or buying something from their establishment will usually help the process along. What could be better than something that is free, beneficial, and helps to reduce waste? Its a win all around.
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| This is a picture of my homemade milk jug coffee ground hauler. This helps me get the grounds from the office to the house without making a mess. Did I mention that it was also free? |
And Why Coffee Grounds?
So why would I want coffee grounds anyway? For starters they contain useful amounts of phosphorus and potassium. They are also a low level source of nitrogen. They contain minor amounts of calcium, magnesium, copper, and other trace minerals, carbohydrates, sugars, some vitamins, and some caffeine. They also help to encourage microbial growth in the soil.
Nitrogen: 2.28
percent
Phosphorus: 0.06
percent
Potassium: 0.6
percent
Keep in mind that coffee grounds are slightly acidic. A neutral pH is 7. Coffee reportedly has a pH of anywhere from 5.2 to 6.9 depending on the type of coffee and how it is prepared. The lower the pH, the more acidic it is. Most plants prefer to be slightly acidic to neutral in the 5.8 to 7 range. Most municipal tap water is kept slightly alkaline (pH greater than 7) to inhibit microorganism growth. So the acidity of the coffee is either not enough to really worry about or will help to keep the pH in the desired slightly acidic pH range.
Coffee grounds can also be used as a pest deterrent. Most people will encircle the base of a plant with used coffee grounds as a pest barrier. The theory is that the caffeine in the grounds negatively affects these pests so they will avoid the soil where the grounds were found. Some of these pests that it has been found useful against include: ants, pill bugs, snails, slugs. In studies it was found that a 1 to 2 percent caffeine solution killed most slugs and snails in two days. Concentrations as low as 0.01 percent repelled them. A cup of coffee contains about 0.05 percent or more caffeine. You can also broadcast the grounds at 2 - 5 lbs per 100 sqft to help run the pests out of the area.
If you have a vermicompost bin and are raising earthworms you can also use the grounds to food. Earthworms are very fond of coffee grounds for some reason.
How Do You Apply?
As mentioned, coffee grounds are especially good for acid loving plants like tomatoes, roses, azaleas, blueberries, evergreens, camellias, and some fruit trees but they are also helpful to the non-acid loving plants as well. Just keep in mind not to add un-brewed grounds directly to plants. Before they are brewed the grounds are too acidic and nitrogen rich so there is a potential to burn the plants.
When applying coffee grounds directly to the soil they can be utilized at rates similar to other organic amendments. Usually a rate of 10-20 lbs (dry) per 1000 sqft will work best.
You can also dilute the grounds with water for a gentle fast acting liquid fertilizer. Use about a half pound can of wet grounds in a five gallon bucket of water and allow it to "brew" for a little bit then apply it around the plants.
Don't forget that the grounds can also be added directly into the compost bin. Don't worry about separating out the filters. Just add them filters and all. Coffee grounds have a carbon to nitrogen ratio of around 20:1 and because the grounds are rich in nitrogen they will provide the bacteria the energy needed to turn the organic matter into compost. This energy will help raise and maintain higher temperatures in the compost pile for longer periods of time which aids in killing pathogens as well.
Other Thoughts?
Below are some additional unverified ways in which you could potentially use the coffee grounds. However you use them just remember to have fun!
1. Soften and add
shine to hair. When washing your hair, rub coffee grounds through wet hair and
rinse. For brown hair, coffee grounds add highlights.
2. Use coffee
grounds as an exfoliant for skin. Pat on skin, massage over skin, rinse.
3. Add coffee
grounds to your skin mask beauty routine.
4. Make homemade
tattoos (temporary) with henna and coffee grounds.
5. Fertilize plants.
Old coffee grounds are nutrient-rich for plants that thrive in an acidic soil.
6. Add used coffee
grounds to the pots of indoor plants.
7. Work used coffee
grounds into your garden soil before seed planting. After your plants start to
emerge, work in coffee grounds near the plants. Used coffee grounds are said to
repel snails and slugs as well as adding nutrients to the soil.
8. Increase your
carrot and radish harvest by mixing seeds with dry coffee grounds before
planting the seeds.
9. Use coffee
grounds to repel ants.
10. Keep cats from
using your garden as a kitty box by spreading used coffee grounds and orange
peels throughout flower beds.
11. Deodorize a
freezer. Place a bowl with used coffee grounds in the freezer to remove
unwanted odors. Add a few drops of vanilla to coffee grounds.
12. Rub coffee
grounds on hands to get rid of smells from chopping or cutting up pungent
foods.
13. Make a used
coffee grounds sachet. Fill old nylons or cheescloth with dry used coffee
grounds. Hang in closets to absorb odors.
14. When you need an
abrasive cleaner, coffee grounds can be used. Be careful of any surfaces that
might stain.
15. Remove furniture
scratches with wet coffee grounds.
16. Got a fireplace?
Sprinkle wet coffee grounds over the ashes to keep from becoming engulfed in
the plume of dust ashes create when you need to remove them.
17. Dye fabric,
paper or Easter eggs. Simply add used coffee grounds to warm water and let sit
a bit to create a dye.
18. After you give
your dog a bath, rub coffee grounds through the coat of your pet. Coffee
grounds are said to repel fleas.
19. Keep bait worms
alive by mixing coffee grounds into the soil before you add worms.
20. Grow mushrooms
on old coffee grounds.
