The beauty of coffee is not only that it tastes good and gives a caffeine kick, but the various other uses it has, even after the extraction process. You’ve definitely heard about coffee scrubs as an additional beauty regime, but have you heard about coffee grounds for plants, being used as fertilizers and compost?
In this article, you’re going to find out the answer to life-long questions such as do coffee grounds help plants grow? and are coffee grounds a good alternative to compost? There are of course various answers to these questions, and not only does it depend on the type of plants you grow but also the location.
It is important to know that some gardeners will have varied opinions on whether this is a good idea or not. As we always say, it is worth testing the method to see if it works for you! Why throw away used coffee grounds when you can put them to good use, and save some money.
If you like hacks and DIY coffee trends, check out how to roast coffee beans at home.
Why is Coffee Good for Plants? (And Potentially Bad)
Coffee grounds are great as fertilizers and other plant health boosters since they contain a number of key nutrients which the plants need to grow. There is roughly 1.5 – 2% nitrogen present in coffee grounds, and they have a pH close to neutral between 6.5 to 6.8 pH level when used.
Using fresh coffee grounds can affect the chemical balance of the soil and do more damage than good. Fresh coffee is highly acidic compared to used coffee grounds that are neutral.
Another benefit when using coffee grounds for the garden is that it attracts worms, and by now you already know how worms are very valuable in boosting plant growth and making the soil healthy. This might be worrying for some gardeners as you would think that coffee grounds would also attract pests, however, it actually acts as a natural pesticide so you don’t have to douse your garden in chemicals.
The main benefit of using coffee grounds is they are basically free (you would buy the coffee anyway). If you don’t purchase coffee grounds, some coffee shops actually give away waste grounds, so it’s always worth asking at your local coffee shop.
Coffee Grounds for Plants Controversy
As with many “life hacks” some people swear by them and some swear against them. It’s whatever works well for you, and some things will work perfectly for you whilst they can not work at all for other people. Many lifelong gardeners have spoken about using coffee grounds in your garden and decided it’s not a good idea. Here’s why:
- It can do more damage than good – Some grounds are thick and can prevent water from reaching the roots of the plants, causing them to die.
- If the acidity is “off” then the plants could be ruined or the growth of plants impacted.
- Caffeine can impact the growth of plants.
The pros and cons of using coffee grounds for plants should be taken with a pinch of salt. Some people don’t follow the advice correctly which can lead to failure, so always read the information and try this hack by the book first. You can read some more about a gardener testing coffee grounds here.
Be careful if you have animals. If animals like to eat the soil or coffee for that matter, caffeine would not have a positive effect on them.
Using Coffee Grounds for Gardening
We have been over why you should and potentially shouldn’t use coffee grounds for plants, let’s talk about what you can actually use the coffee grounds for in your garden.
1. Using Coffee Grounds as Compost
As mentioned previously, why would you throw away used coffee grounds when you can use them for your compost pile? Compost contains a good level of Nitrogen of around 1.5 – 2% which is a good addition to a compost bin/pile. They also provide calcium, magnesium, and other useful minerals.
Coffee grounds are considered green material which may be misleading as they are brown. For those not-so-savvy gardeners out there, compost must be made up of green and brown material to be effective. You should be aiming for 4:1 brown to green, otherwise, your compost pile will not work.
2. Using Coffee Grounds as Fertilizer
It is important that used coffee grounds are applied as fertilizer due to the acidity levels mentioned before. If you want to use fresh grounds, rinse them with warm water for a while to neutralize the acidity.
Coffee grounds contain a lot of essential minerals to boost plant growth. These minerals include calcium, chromium, iron, nitrogen, magnesium phosphorus, and potassium. In order for you to use coffee as fertilizer, all you need to do is to sprinkle coffee grounds into the soil circling the plants. It is important not to use too much, as you can prevent water and other essential nutrients from reaching the roots.
By now, you already know the importance of worms for your plants, but did you also know that you can attract worms using coffee grounds as your fertilizer? This can also be beneficial to your garden so is worth trying.
3. Using Coffee Grounds as a Mulch
Mulch is a coating of material placed on top of the soil as a covering. Mulch is great for preserving soil moisture, boosting plant fertility, and soil health. It is also great for inhibiting weed growth. There are two types of mulch used in gardening: organic and inorganic.
Used coffee grounds are one of the best organic materials that can be used as mulch. But you need to keep in mind that using the pure coffee ground as a top layer can be dangerous, The reason for this is that just like clay soil, coffee grounds consist of tiny particles that can clump together. When these coffee grounds clump together, this will prevent any water to pass through them, causing the plants to die.
The best way to use coffee grounds as mulch is to mix them with other organic materials, just like compost or leafmold. Another way you can do to prevent coffee grounds from clumping together is to rake them into the top layer of soil.
4. Using Coffee Grounds for Plants
Be very careful when using coffee grounds for plants especially if you have pets that love to get a taste of anything that smells good. In small doses, coffee grounds are not that lethal but in large doses, they can be detrimental. The best thing that you need to do is bury the coffee grounds in your compost and avoid layering it on top of the soil.
Coffee grounds have been used by gardeners for a long time, and it has been proven to improve the health of the soil and help repel pests and insects. But not all methods and conditions are good for the plants.
You have to keep in mind that when you do decide to use your used coffee grounds for your plants, don’t use them on seedlings or newly sprouted plants since the caffeine contained in coffee grounds can inhibit plant growth.
5. Using coffee grounds as an insect repellent
Another great use of coffee is insect repellent. By now, you already have an idea of how versatile coffee grounds can be and how they’re not only great for giving you your daily dose of energy but also for helping out your plants. If you have pest or insect problems like snails and slugs, then you should add coffee grounds as an additional guard against pesky pests.
The explanation for this is that the bugs hate the caffeine present in coffee grounds, and it negatively affects them, that’s why they always avoid the soil covered with coffee grounds. There have been several people who claim that coffee grounds also help keep cats away from the coffee-covered soil. This is beneficial for people who own pets, and flower and vegetable beds.
6. Using coffee grounds for acid-loving plants
Fresh coffee is quite acidic as already mentioned, this may be bad news for people who have sensitive stomachs, but this is great for acid-loving plants. If you own any Hydrangeas, Azaleas, Blueberries, Carrots, or Radishes, then it’s highly recommended for you to use fresh (unbrewed) coffee grounds to boost your plant’s life.
Just be careful not to overload your tomatoes with coffee grounds since tomatoes only like slightly acidic soil and too much coffee ground will kill your tomatoes.
You don’t have to throw away your used coffee grounds. Even though you’ve already extracted the best qualities of the coffee and drank the freshest cup of joe, there are still nutrients and essential components that remain in used coffee grounds.
Instead of throwing it away, use your coffee grounds as compost, fertilizers, mulch, or even insect and pest repellent.