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, so 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.
