How to Use Coffee Grounds for Plants
If you’re a coffee lover, don’t throw away those used grounds just yet—your garden might be able to utilize them. Properly utilized, coffee grounds can be a great natural fertilizer and soil amendment, from outdoor beds to indoor houseplants.
You’ve probably heard that coffee grounds are good for plants. But do they really work? And if so, how do you use them to reap their benefits? Some gardeners swear by them, while others are less convinced, citing potential drawbacks. The truth is, it depends on how you use them and what your garden needs.
To get the most out of your coffee waste, it’s best to stick with tried-and-true gardening applications and avoid the myths that are prevalent. Here’s how to maximize the benefits of coffee grounds in your soil, garden, and houseplant maintenance.
Why Coffee Grounds Are Good for Plants
Coffee grounds contain wonderful nutrients, including nitrogen, potassium, phosphorus, magnesium, and calcium. All of these nutrients are important to plant health, especially nitrogen, which produces healthy leaves and sturdy stems.
In addition, coffee grounds:
- Improve soil by improving aeration and water retention
- Improve drainage in clay soils
- Make composting easier by providing nitrogen that improves microbial growth
How to Use Coffee Grounds in Your Garden
1. Blend Into Potting Mix or Soil
Blend composted coffee grounds into garden soil or potting mix to provide nutrient content and soil structure. Composting first is important—it reduces acidity and breaks down caffeine.
2. Mulch Application
Blend coffee grounds with dry grass clippings, straw, or leaves to create a successful mulch. It accomplishes the following:
- Retains moisture
- Suppresses weeds
- Regulate soil temperature
Avoid using coffee grounds alone as they will settle and form a barrier that won’t allow water and air in the soil.
3. Liquid Fertilizer
Steep 2 cups of used coffee grounds in 5 gallons of water overnight to create a natural “coffee tea.” Use this to water garden beds or plants in containers to give them a gentle shot of nutrients.
4. Compost Addition
Coffee grounds are a “green” compost. Combine them with “brown” material like dried leaves or paper to create nutrient-rich compost for your plants.
What to Avoid
Don’t Use Around Seedlings
Coffee grounds are too acidic for delicate seedlings and may stunt their growth. Wait until plants are well established.
Don’t Use Near Acid-Sensitive Plants
Don’t use near plants that prefer alkaline or neutral soil, such as:
Be Careful in Wet Spots
As they retain water, coffee grounds can promote fungal disease in poorly draining soils. Use sparingly on wet or fungus-prone areas.
Use Moderately
Strong solutions of coffee grounds can pack the soil and impede water/air flow. Mix always with other composted materials.
Tips for Practical Use
- Compost first to neutralize acidity and caffeine
- Mix in well with mulch or soil materials
- Use on plants that adore nitrogen like azaleas, rhododendrons, roses, and carrots
- Do not apply to seedlings and acid-sensitive plants
- Try liquid fertilizer for a safe, easy dose of nutrients
Final Thoughts
Coffee grounds are a fantastic, eco-friendly way to fertilize your garden—if used correctly. Once you understand when, where, and how to apply them, you can transform your morning coffee habit into a phenomenal gardening trick.
Have you ever employed coffee grounds in your garden? Share your advice and experience in the comments—we’d love to hear from you!
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