How to Use Coffee Grounds in Your Garden

Tired of discarding coffee grounds every morning? With their rich nutritional content, coffee grounds can help improve the fertility of your garden soil. Due to their natural acidity and high levels of nutrients like nitrogen and potassium, coffee grounds are an excellent choice for alkaline soil or nutrient-poor gardens. With a little creativity, you can use coffee grounds for various purposes in your garden.

Adding coffee grounds to compost. One of the easiest ways to make use of leftover coffee grounds is by adding them to your compost pile. Not only do they provide additional organic matter, but coffee grounds also help accelerate the decomposition process. You can easily take advantage of this benefit by tossing the grounds into your compost heap.

• There are two main types of compost materials: 'green' compost and 'brown' compost. Coffee grounds are considered 'green' compost, along with other wet and nutrient-rich materials. If you add a lot of coffee grounds to your compost, you may need to balance it by adding 'brown' compost, such as dry, bulky materials like dry leaves, newspaper, straw, corn husks, sawdust, etc.

Directly add coffee grounds to the soil to increase acidity. Coffee has a pH level of about 5.1, which is relatively acidic compared to most garden soils. While this level of acidity may be too high for some plants, it's ideal for others that require more acidic conditions. Simply sprinkle a handful of coffee grounds around the roots of your plants at the start of the planting season to boost acidity. Blueberries, cranberries, and citrus fruits thrive in soil enriched with coffee grounds. Other plants that enjoy coffee grounds include camellias, gardenias, and azaleas.

• Some flowers may change color when grown in highly acidic soil. For example, adding coffee grounds to a hydrangea plant could cause it to produce blue flowers.

Consider adding lime to balance the pH of coffee grounds. As mentioned earlier, the natural acidity of coffee grounds may not be suitable for 'average' garden soil. To reduce the acidity, you can mix a pinch of lime with the coffee grounds. Lime is naturally alkaline (opposite of acid) and will neutralize the acidity in the coffee grounds. This allows you to add coffee grounds directly to your garden as a mulch or soil conditioner.

• Lime is often sold under the name 'garden lime' or 'agricultural lime'. It's readily available at garden stores at a relatively low price.

Use coffee grounds to supplement the nutrients in the soil. Acidity is not the only benefit of coffee grounds. They also contain many essential nutrients that help plants grow strong and healthy. Therefore, if your garden is lacking in nutrients, coffee grounds are an excellent option. Here's what you need to know:

• Coffee grounds are rich in:
• Nitrogen
• Magnesium
• Potassium
• Coffee grounds are not rich in:
• Phosphorus
• Calcium

Another option is to use coffee grounds to make a liquid fertilizer for your plants. Coffee grounds aren't just for direct application in the garden – you can also turn them into a liquid fertilizer. Place a handful of coffee grounds into a bucket of water. Let it sit in a cool place (like the garage) for 1-2 days. The resulting solution will have an amber color. Strain out the coffee grounds and use this solution to water your plants.

• This solution has a similar acidity and nutrient content as regular coffee grounds, so use it cautiously on plants that don't require much nitrogen, potassium, and prefer less acidic conditions.

Use coffee grounds to repel pests. Slugs and snails can munch on your valuable plants, but they’re not fond of coffee grounds. Sprinkle a handful of coffee grounds around the base of the plants you want to protect. If you're concerned about increasing the soil's acidity, you can scatter the grounds in a ring farther away from the plant’s root system.

• It is believed that coffee grounds work due to the caffeine they contain, which is harmful to these pests.

Use coffee grounds to keep cats out of the garden. Coffee grounds don’t just help deter tiny pests. You can also use them to keep cats from disturbing your delicate plants. Apply coffee grounds in the same way you would to repel slugs—sprinkle them around the plants you want to protect. The effect of increased soil acidity is unavoidable, depending on how much coffee grounds you use.

Use coffee grounds as food for worms. If you raise earthworms, you have a great opportunity to make use of coffee grounds. Worms enjoy eating coffee grounds, so feel free to add a lot of them to your worm bin or compost heap. Just remember, coffee grounds should be part of a balanced diet for the worms: include vegetable scraps, fruit peels, newspaper, leaves, and similar items along with the coffee grounds.

Use coffee grounds to prevent fungal infections. There’s evidence that coffee grounds can help combat certain fungi that harm plants. A thin layer of coffee grounds can prevent fungi such as Fusarium, Pythium, and Sclerotinia from attacking plant roots. Tomatoes, eggplants, and peppers are especially vulnerable to fungal infections, so coffee grounds are a great option for these plants.