1. Pest Repellent
Sprinkle used coffee grounds around your plants to protect them against destructive garden pests like ants, snails, and slugs. It has even been said that old grounds mixed with dried orange peel will keep away some small mammals like cats (though Felix can be a tough customer. If coffee and orange peel doesn’t work, try rosemary oil instead!)
2. Fertilize Your Garden
If you grow azaleas, hydrangeas, rhododendrons, camellias, roses, or other acid-loving plants, then used coffee is the fertilizer for you! Mix your old grounds with dead grass clippings, brown leaves, or dry straw to neutralize some of the acidity, the spread them around your plants. Used coffee grounds add nitrogen and potassium to the soil (the first and third numbers in the fertilizer formula: N – P – K) as well as a boost of magnesium which all plants need to stay healthy.
Just remember that this fertilizer lacks phosphorus and calcium so it isn’t ideal for encouraging blooms and fruiting. You’ll need to add lime or wood ash to the mix if you want to create a complete fertilizer using old coffee grounds.
3. Compost It for Later
If you don’t have a use for coffee ground fertilizer right away, go ahead and throw it on the compost heap. Coffee grounds make excellent “green” matter as they are rich in nitrogen. Also, beneficial worms may be attracted to your compost with the addition of old coffee. Just be sure to limit the amount of grounds that you add to your pile so that you don’t throw off the ratio of “green” to “brown” matter. Check out this great guide for keeping your compost balanced.
4. Caffeine for… Carrots?
If you love carrots and you love coffee, then you’re in business! Your carrots will love you back if you share your old grounds with them at planting time. Before you sow carrot seeds, mix them with some old dried coffee grounds to give them an energy boost right from the get-go. You’ll get bigger and better produce with the added bonus of deterring pests that want to eat your carrots before you do.