Should You Put Coffee Grounds on Your Plants?
If you are a coffee lover and a plant parent at the same time, you might want to recycle your coffee grounds and also potentially help your garden or houseplants grow. While coffee grounds can benefit your plants, it’s not always as easy as sprinkling fresh grounds on top.
Although brewed coffee is quite acidic, the used grounds are fairly neutral, which means they probably won’t do much harm or benefit in terms of pH. However, trapped caffeine in the coffee grounds can inhibit seed germination and growth . Additionally, placing soil on top of your plants can interfere with proper air and water circulation and soil penetration.
However, when used correctly, coffee grounds can improve soil structure and ward off pests (and plant-loving cats). So what do you do instead?
Add soil to compost or mulch
An indirect approach will allow your plants to reap the benefits of the used coffee grounds without the risk of stunted growth. Mix soil with mulch or compost heap, which can then be used to improve the soil. Make sure your entire compost bin is n’t made with coffee grounds, though – Treehugger recommends one part coffee versus four parts other organic matter.
Use small amounts right away
If you don’t have homemade compost, you can sprinkle a small handful of soil on top of the soil and mix it gently to form a first centimeter or two. Or, you can make a “tea” for indoor and container plants using 2 cups of ground coffee in 5 gallons of water, infusing overnight.
Add to worm cart
If you have earthworm compost, coffee grounds are a great food.
The bottom line of using coffee grounds in gardening is that less is better, and better indirectly. Don’t just dump dirt on top of your plants every morning.