As a heavy coffee lover who can't start a new day without a cup of freshly brewed coffee, I always feel a pang of regret every time I throw away the used coffee grounds. At the same time, as a succulent plant enthusiast with a windowsill filled with adorable little succulents, I couldn't help but wonder: Could these two things I love be combined? After several months of experimentation and exchanging experiences with other "plant parents," I finally figured out whether succulent plants would truly thrive with coffee grounds.

The Appeal of Coffee Grounds

Theoretically, coffee grounds are the perfect plant fertilizer. They are rich in nitrogen, a key nutrient for healthy plant growth, and can also add organic matter to the soil. Additionally, using coffee grounds to nurture plants is an exceptionally eco-friendly practice, transforming your daily coffee ritual into a zero-waste gardening activity. However, before you pour coffee grounds onto your succulents like Echeveria, let's first understand the science behind it.

Acidity Test

Many people mistakenly believe that coffee grounds make soil extremely acidic. In reality, fresh coffee grounds have a pH of around 6.5, which is mildly acidic. However, as they decompose, their acidity weakens, approaching neutrality. Succulents thrive in well-draining soil with a pH between 6.0 and 7.0, which is mildly acidic to neutral, so they can theoretically adapt to this pH range. However, if you use too much and cover the succulents with a thick layer of fresh coffee grounds, you are creating an ideal environment for mold and pests to thrive.

Drainage Issues

Succulents are essentially "desert dwellers" and are most afraid of waterlogged soil. If you use a large amount of coffee grounds, over time, they will compact and form clumps, leading to excessive water retention in the soil. This is the primary cause of the fatal root rot disease in succulents. Imagine staying in a damp, sticky bed—your succulents certainly wouldn't want that either!

Safe Use of Coffee Grounds

Does this mean coffee grounds should be discarded? Of course not! The following methods can safely utilize coffee grounds as a helpful tool for succulent care:

1. Compost first: Mix used coffee grounds with other kitchen waste (such as eggshells and banana peels) and yard waste. After at least one month of composting, add a small amount of coffee grounds (no more than 10% of the soil volume) to the succulent pot. This allows you to fully utilize the nutrients in the coffee grounds without worrying about mold growth or drainage issues.
   
2. Local application: Spread a thin layer of dried coffee grounds on the soil surface around the succulent plants. This not only repels slugs and snails (though uncommon indoors, they can be a problem when growing succulents outdoors) but also slowly releases nutrients. Remember, this layer of coffee grounds should not exceed one-quarter of an inch in thickness.
   
3. Making liquid fertilizer: Soak coffee grounds in water for 24 hours to create "coffee tea." Strain the liquid, then dilute it with an equal amount of clean water for watering succulents. This method gently provides succulents with abundant nutrients without affecting soil conditions

Other care options

If you're still hesitant to use coffee grounds, there are many other effective ways to care for succulents. Specialized fertilizers designed for cacti and succulents have scientifically balanced nutrient ratios. Organic fertilizers, such as worm castings or fish protein emulsions, are safe and natural alternatives. You can also add perlite or pumice to the soil to improve drainage or report the succulents every 1–2 years to maintain soil fertility.

In summary, succulents can benefit from coffee grounds when used in moderation, but care should be taken to use them appropriately. Just as brewing coffee requires care, nurturing succulents demands love and balance. If you're unsure, stick to proven, reliable methods. After all, healthy succulents are worth celebrating with a toast the next time you enjoy a cup of coffee!