Used Coffee Grounds: The Plants That Love This Fertilizer (And the Ones That Hate It)

Using coffee grounds as a fertilizer is a popular and eco-friendly practice among gardeners. Coffee grounds are rich in nutrients and organic matter, making them a valuable addition to the soil. However, not all plants benefit from this type of fertilizer. Here’s a guide to help you understand which plants love coffee grounds and which ones don’t.

Benefits of Coffee Grounds as Fertilizer

Coffee grounds are packed with essential nutrients such as nitrogen, potassium, and phosphorus, which are vital for plant growth. They also improve soil structure, increase acidity, and encourage beneficial microorganisms. Here’s how coffee grounds benefit plants:

  • Nutrient Supply: Coffee grounds release nitrogen slowly, providing a steady supply of nutrients to plants.
  • Soil Structure: Adding coffee grounds to soil improves its texture and drainage.
  • Microbial Activity: Coffee grounds promote the growth of microorganisms that help break down organic matter and enrich the soil.
  • Mulching: Used as mulch, coffee grounds help retain soil moisture and suppress weeds.

Plants That Love Coffee Grounds

Certain plants thrive with the addition of coffee grounds due to their nutrient needs and preference for acidic soils. Here are some plants that love coffee grounds:

  1. Acid-Loving Plants
    • Azaleas: These flowering shrubs thrive in acidic soil, and coffee grounds can help maintain the right pH level.
    • Rhododendrons: Like azaleas, rhododendrons prefer acidic conditions and benefit from coffee grounds.
    • Blueberries: These berries grow best in acidic soil, and coffee grounds can help provide the necessary conditions.
    • Hydrangeas: Coffee grounds can affect the color of hydrangea flowers, often resulting in more vibrant blues and purples.
  2. Vegetables
    • Carrots and Radishes: Coffee grounds can help improve the texture of the soil, making it easier for these root vegetables to grow.
    • Tomatoes: Although tomatoes don’t need acidic soil, coffee grounds can provide a nitrogen boost, which is beneficial for their growth.
  3. Herbs
    • Rosemary: This herb enjoys well-draining, slightly acidic soil, making coffee grounds a good match.
    • Sage: Similar to rosemary, sage thrives in soil enriched with coffee grounds.

Plants That Hate Coffee Grounds

While many plants benefit from coffee grounds, some do not due to their sensitivity to acidity or other factors. Here are some plants that dislike coffee grounds:

  1. Alkaline Soil Plants
    • Lavender: Prefers alkaline soil, and coffee grounds can make the soil too acidic.
    • Aloe Vera: Thrives in well-draining, neutral to slightly alkaline soil.
  2. Root Crops
    • Beets: Coffee grounds can alter the pH balance of the soil, which may negatively affect beet growth.
    • Potatoes: Prefer slightly acidic to neutral soil but too much coffee grounds can lead to overly acidic conditions.
  3. Sensitive Vegetables
    • Beans: Coffee grounds can inhibit the growth of beans due to the increased acidity and potential allelopathic effects.
    • Peas: Similar to beans, peas can be adversely affected by the acidity of coffee grounds.

How to Use Coffee Grounds in Your Garden

  1. Composting: Add coffee grounds to your compost pile to create a balanced and nutrient-rich compost. They contribute nitrogen, which is essential for composting.
  2. Direct Application: Sprinkle used coffee grounds around the base of plants that love acidic soil. Be sure to mix them into the soil to prevent them from forming a crust.
  3. Liquid Fertilizer: Steep coffee grounds in water to create a mild, acidic liquid fertilizer. Use this to water your acid-loving plants.


Used coffee grounds can be a fantastic addition to your garden, providing essential nutrients and improving soil health. However, it’s important to know which plants will benefit and which might suffer from this type of fertilizer. By understanding the needs of your plants, you can use coffee grounds effectively to create a thriving and balanced garden.

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