- 1Allow hot coffee grounds to cool completely before composting (prevents killing beneficial organisms)
- 2Include unbleached paper coffee filters whole—they're 100% compostable
- 3Check tea bag composition (many contain 20-30% polypropylene plastic)
- 4Remove metal staples and string tags from tea bags before composting
- 5For K-Cups, separate paper filter and grounds from plastic pod (recycle pod separately)
- 6Spread grounds in 1-2 inch layers—thick clumps form water-resistant mats
- 7Mix 1 part coffee grounds with 3-4 parts carbon materials (leaves, shredded paper, cardboard)
- 8Add grounds to worm bins in moderation (no more than 25% of weekly feed)
- 9Store used grounds in sealed container if not composting immediately
- 10Collect grounds from local coffee shops via Grounds for Your Garden programs
- Home compost bins and tumblers
- Worm composting (vermicomposting) bins
- Municipal curbside organics collection
- Community garden composting programs
- Starbucks Grounds for Your Garden program (free pickup)
- Local coffee shops and cafes (call to arrange pickup)
- Farmers markets with composting booths
- Office composting programs
Coffee grounds are nitrogen-rich green materials containing 2% nitrogen, 0.3% phosphorus, and 0.3% potassium—similar NPK ratio to commercial fertilizers. Despite popular belief, used coffee grounds are nearly pH neutral (6.5-6.8); the acidity is in the liquid, not the grounds. They're perfect for worm bins as grounds provide grit for worm digestion and nitrogen for growth. Coffee grounds suppress fungal rots and wilts while deterring slugs, snails, and ants. They attract earthworms which aerate soil and create nutrient-rich castings. Tea leaves contain 4.4% nitrogen and trace minerals (manganese, potassium, zinc) plus tannic acid that helps acidify alkaline soils over time.
Americans consume 400 million cups of coffee daily, generating 2-3 million tons of spent coffee grounds annually. Only 1% gets composted—99% goes to landfills where it produces methane. Composting coffee grounds prevents 0.5-0.8 pounds of CO2 equivalent emissions per pound. Starbucks' Grounds for Your Garden program diverts 30 million pounds annually, preventing 15,000+ tons of greenhouse gases. Coffee grounds in compost improve soil water retention by 15-20%, reducing irrigation needs. Tea production generates 6 million tons of waste yearly; composting tea bags diverts this from landfills while adding valuable polyphenols and antioxidants to soil.
- Spread directly on garden soil as slow-release fertilizer (1/4 inch layer)
- Mix into potting soil for container plants (10-20% coffee grounds)
- Create compost tea by steeping grounds in water for 24 hours
- Add to worm bins as protein-rich feed (mix with bedding)
- Use as natural pest deterrent around plants (deters slugs, snails, ants)
- Sprinkle around acid-loving plants (azaleas, blueberries, roses, hydrangeas)
- Mix with coconut coir for seed starting medium
- Absorb refrigerator and freezer odors in open container
- Create DIY body scrub (mix with coconut oil and sugar)
- Use as natural furniture scratch cover (darkens wood scratches)
- Grow mushrooms (oyster mushrooms thrive on coffee grounds)
- Donate to local community gardens and urban farms
- Feed to composting worms (protein source for reproduction)
Accepted
- Used coffee grounds (any roast, decaf, flavored)
- Unbleached paper coffee filters (brown or natural)
- Bleached white coffee filters (compostable but slower)
- Paper tea bags (natural fiber only—check packaging)
- Loose leaf tea and tea leaves
- Herbal tea blends and botanicals
- Yerba mate and mate tea leaves
- Chai tea bags and spice residue
- Green tea, black tea, oolong tea leaves
- Rooibos and caffeine-free tea bags
- Coffee chaff and roasting waste
- Espresso pucks and portafilter grounds
- French press coffee grounds
- Pour-over and drip coffee grounds
- Cold brew coffee grounds
Not Accepted
- K-Cup pods (separate contents first, recycle #5 plastic shell)
- Nespresso capsules (aluminum—recycle through Nespresso program)
- Coffee creamers and dairy products (attracts pests in home bins)
- Sugar packets and artificial sweeteners
- Plastic tea bag wrappers and packaging
- Silken pyramid tea bags (often contain PLA plastic)
- Tea bags with metal staples (remove staples first)
- Flavored coffee grounds with synthetic additives
- Coffee with excessive milk or cream added
- Disposable coffee cups and lids
- Plastic stirrers and straws
Estimated value: Free from coffee shops; finished compost with coffee grounds worth $30-60 per cubic yard. Home composting coffee saves $100-200 annually in fertilizer costs.
Do coffee grounds make compost too acidic?
No—this is the #1 composting myth! Used coffee grounds have a nearly neutral pH of 6.5-6.8. The acidity is in the brewed coffee liquid, not the grounds. Fresh (unbrewed) grounds are acidic (pH 5.0-5.5), but brewing extracts the acids. You can safely add coffee grounds to compost without worrying about pH.
Can I put too many coffee grounds in my compost?
Yes. Coffee grounds should comprise no more than 20-25% of your compost volume. They're considered 'green' nitrogen materials, so balance them with 'brown' carbon materials like shredded leaves, cardboard, or wood chips. Excessive coffee grounds create water-repellent mats and can introduce too much nitrogen, causing ammonia odors.
Are K-Cups and coffee pods compostable?
Not entirely. Standard K-Cups have plastic #5 shells that must be recycled separately. You need to peel back the foil lid, dump the grounds and paper filter into compost, then recycle the plastic cup. Some brands now make 100% compostable pods (check for BPI certification). Nespresso aluminum capsules go to special recycling, not compost.
Which tea bags contain plastic?
Many tea bags contain 20-30% polypropylene plastic to seal the bags with heat. Pyramid bags, silken bags, and some sealed bags often have plastic. Paper string-and-tag bags are usually plastic-free. Brands like Pukka, Clipper, and Yogi use compostable bags. When in doubt, tear open the bag and compost just the tea leaves.
Can I use coffee grounds directly in my garden without composting?
Yes! Coffee grounds work as a slow-release fertilizer. Spread a thin layer (1/4 inch) around plants and gently work into topsoil. Don't pile thick layers—they form water-repellent crusts. Coffee grounds work best for acid-loving plants like blueberries, azaleas, rhododendrons, and roses. They suppress fungal diseases and deter slugs and snails.
Do coffee grounds attract or repel pests?
Coffee grounds repel slugs, snails, ants, and cats while attracting beneficial earthworms. The caffeine residue (0.3-1.2%) is mildly toxic to slugs and snails. However, coffee grounds can attract fruit flies if not properly managed—always bury them in compost or cover with brown materials.
Where can I get free coffee grounds for composting?
Starbucks offers free grounds through 'Grounds for Your Garden'—ask at the counter for a 5-pound bag. Many independent coffee shops, cafes, and office break rooms happily give away used grounds. Bring your own container and ask if they'll save grounds for you.