Are Coffee Grounds Good for Plants?

Are you looking for a way to utilize your spent coffee grounds from last night’s espresso? Some plants would enjoy that acidic soil to help them grow, which might surprise you. Here are some things to understand about using coffee grounds with your plants!

What Makes Coffee Grounds Good for Some Plants?

The primary benefactor of adding coffee grounds to a plant’s soil is the nutrients it adds. Coffee, like most organic materials, is nutrient-rich. Before finding themselves in your mug, coffee grounds are around 10% nitrogen.

After breaking down in the soil, spent grounds can promote essential nutrients for plant growth like calcium, magnesium, and nitrogen. For soils with a naturally high pH level, the effects may be minimal, though.

Can Coffee Grounds Go into Your Mulch?

Coffee grounds make for an effective additive to your mulch. While composted coffee grounds are the most effective, used coffee grounds, even fresh coffee grounds can go in mulch to promote healthy plant growth.

It is best if your mulch is less than 20% coffee grounds to avoid issues with caffeine and the acidity level. One tip is to use a soil testing kit to get an accurate reading before adding coffee grounds to your mulch. While coffee may not surprise you as acidic, spent grounds are even more acidic, so you need to be careful with how much you add to the mulch.

Can Coffee Grounds Suppress Weeds?

Interestingly, coffee grounds can help suppress weed build-up in your plant garden. However, before you start dumping coffee grounds everywhere, you need to understand what plants like vs. don’t like coffee grounds.

Which Plants Benefit From Coffee Grounds?

Acid-loving plants will benefit the most from spent coffee grounds. Some plants that enjoy coffee grounds include snake plants, lilies, azaleas, roses, and cabbages. Other plants that want coffee grounds include African violets, golden pothos, parsley, and zz plants.

Which Plants Do Not Like Coffee Grounds?

If acidic soil likes coffee grounds, then you can imagine how much alkaline soil hates it. Some plants that don’t enjoy coffee grounds include tomatoes, orchids, lavenders, and the century plant. Other plants that don’t like coffee include black-eyed susans, and yuccas.

Tip to Get the Correct Amount of Coffee Grounds in Your Soil

Using a soil testing kit will be critical when it comes to adding coffee grounds to your plants. For example, adding coffee grounds to a plant will dramatically increase the nitrogen level. Finding the suitable pH-balanced soil for your plant differs from nutrient deprivation or exposure to otherwise absent toxic elements.

Is Too Much Coffee Grounds Bad for Plants?

You need to be careful which plants you use ground coffee with, as we mentioned earlier. For example, we know that coffee contains high amounts of nitrogen, and nitrogen is necessary for plant growth. Too much nitrogen can negatively affect the flower or fruit.

Another issue to be aware of is caffeine. Caffeine occurs in some plants, where its role is to attack and kill competing flowers. Adding more than 20% ground coffee grounds to your mulch, especially fresh coffee, will actively prevent plant growth and can even kill the plant altogether. Even spent coffee isn’t safe from caffeination, with one study showing spent coffee grounds consist of anywhere from 4%-8% caffeine content.

Can Coffee Grounds Keep Away Bugs and Pets?

One benefit of putting coffee grounds in your plant is restricting bugs from attacking your plant. Coffee grounds can keep away bugs because they are a bit difficult for bugs to crawl on, which can help keep them away from your plant altogether. Also, some people claim that adding coffee grounds kept their cats from going after their plants, which can be another benefit.

Final Verdict: Are Coffee Grounds Good for Plants?

In summary, you will find plenty of articles going over the benefits and disadvantages of using coffee grounds for plant care. Such seems to be the consensus on the matter. It is not uncommon to read that ground coffee can bolster physical soil properties while falling short of being beneficial towards plant growth.

However, the general and safe rule is that coffee grounds can help certain plants grow that enjoy more acidic soil. To best use coffee grounds in your plants, you should use a soil testing kit to ensure you are staying in the suitable soil levels for your plants. Once you get this process down, you will have a good understanding of what plants can benefit from coffee and which ones won’t.

Finally, like anything with plants, it comes down to what works best for you. If you succeed in using coffee grounds in your plants that can tolerate the acidic soil, keep using it. If you discover that some of your plants are not doing as well with coffee grounds, consider getting a soil testing kit to see if you are adding too much coffee to the soil or mulch that might be causing the issue.