How to Upcycle Used Coffee Grounds in the Garden
Coffee grounds may seem like a waste product after brewing your morning cup of joe, but they can actually provide some great benefits for your garden. Upcycling used coffee grounds keeps them out of landfills and puts their nutrients to work in your soil.
Why Use Coffee Grounds in the Garden?
Coffee grounds contain essential nutrients that are great for your plants, including:
Nitrogen – Coffee grounds are rich in nitrogen, which is crucial for healthy green growth and chloroplast development in plants. The nitrogen boosts foliage growth.
Phosphorus and potassium – These nutrients promote flower and root growth. They help plants absorb other nutrients.
Calcium and magnesium – Necessary for strong cell walls and fruit growth. They also help plants uptake nitrogen.
Antioxidants – Coffee contains disease-fighting antioxidants. These can ward off fungal infections in plants when added to soil.
Some other benefits of using coffee grounds in your garden:
- Improves soil structure and aeration
- Helps soil retain moisture
- Deters pests like slugs and snails
- May increase earthworm activity when added over time
So coffee grounds provide a range of key nutrients and compounds to improve overall soil health and plant vigor. It’s an easy way to upcycle and enrich your garden soil for free!
What Plants Like Coffee Grounds?
Most plants can benefit from used coffee grounds in moderation. Some particular plants that love a boost of java grounds include:
- Vegetables like tomatoes, peppers, carrots, and radishes
- Roses, azaleas, ** hydrangeas, gardenias, camellias** – flower growth
- Blueberry bushes and fruit trees – bigger harvests
- Ferns and palms – thrive on the acidity
However, coffee grounds may not be ideal for plants that prefer more alkaline soils like brassicas (cabbage, kale) and legumes (beans, peas). Start with small amounts to test.
How Much Coffee Grounds to Use
While coffee grounds have excellent nutrients for plants, too much can negatively impact pH and nitrogen levels. Follow these tips:
- Mix grounds into soil in thin layers, no more than 1/4 inch deep
- Apply sparingly around sensitive seedlings and sprouts
- Limit to 20% by volume when mixed into potting soil
- Alternate coffee grounds with high carbon amendments like leaves
Also, be sure to use only fresh coffee grounds. Leftover wet grounds can grow mold and harm plants. Sprinkle dry used grounds right onto the soil.
When and How to Apply Coffee Grounds
Coffee grounds can be worked into garden beds in a few simple ways:
Top dress annually – Lightly sprinkle 1/4 inch over soil before planting each spring. Mix in lightly.
Mix into new garden beds – Till up to 20% dry grounds into the top 6 inches of soil before planting.
Mix into pots and planters – Add 10-20% used coffee grounds into potting mixes. Replenish annually.
Side dress mid-season – Sprinkle 1/4 inch around veggies and flowers and lightly mix into top soil.
Mulch around acid-lovers – Apply a heavy layer of wet grounds around rhododendrons, azaleas, blueberries.
Compost pile activator – Mix with dry leaves to balance “greens” and “browns.” Speeds decomposition.
Apply grounds in the early spring before planting or mid-season as a nutritional boost. Avoid adding large amounts right before seeding or heavy rains.
Always water gently after applying to help wash nutrients into the root zone while minimizing runoff. Avoid heavy watering for a few days.
Storing Used Coffee Grounds
To save up used grounds for garden use:
Let grounds dry fully on a newspaper or tray before storage.
Keep in a sealed tub, bucket, or bag in a cool, dark place.
Use within 2 weeks for the highest nutrient level.
Freeze extra in bags to preserve nutrients for gradual use. Thaw before using.
Don’t store wet grounds. They can quickly grow mold.
With the right technique, used coffee grounds can be a sustainably sourced nutritional boost for most gardens. Upcycle your morning brew to reap the soil improving benefits!