How to Use Coffee Grounds in Your Garden

Using Grounds as a Soil Supplement

Add coffee grounds to your compost. One of the simplest ways to use leftover grounds is to add them to the rest of your compost. In addition to providing extra organic matter, coffee grounds are able to speed up the decomposing process in compost. Getting this benefit is as easy as pouring the leftover grounds into the compost pile and mixing to incorporate them. Quantities up to 1/4 and 1/3rd of the compost pile have been recommended. There are two main types of composting materials: "green" compost and "brown" compost. Coffee grounds are considered to be "green" compost along with other wet, nutrient rich materials. If you add a lot of coffee grounds to your compost, balance it out by adding some "brown" compost as well — dry, bulky materials like dry leaves, twigs, newspaper, straw, corn husks, sawdust, and so on. Due to phytotoxins in the used coffee grounds, compost made with used coffee grounds may take 6 months to a year to mature and break down the phytotoxins.

Use coffee grounds to add nutrients to your soil.They are rich in several nutrients that are critical to healthy plants, so if your garden lacks these, coffee grounds are an excellent choice. See below: Coffee grounds are rich in: Nitrogen Magnesium Potassium Coffee grounds are not rich in: Phosphorous Calcium

Optionally, make a liquid plant food. You don't need to use the coffee grounds themselves in your garden — you can also make a nutritious plant food from them and use it instead. To do this, place a handful of coffee grounds into a bucket of water. Let it sit in a cool, out-of-the-way place (like your garage) for a day or two. It should create a nice amber-colored liquid. Strain the remaining grounds out, then use the liquid to water your plants. It will have the same nutrient content as normal coffee grounds, so use it with caution if your plants don't require nitrogen, potassium, etc.

Using Grounds for Alternate Tasks

Use grounds to deter pests. Slugs and snails can chew up your most prized plants, but they are not fond of coffee grounds. Sprinkle a handful of grounds around the bases of plants you want to protect. If you're worried about phytotoxic effects on the soil, make a solid ring of grounds farther away from the base. It's thought that this works because the caffeine in the coffee grounds hurts these pests.

Use grounds to keep cats out of your garden. Coffee grounds aren't just good for tiny pests. They can also be used to keep feline friends from playing in your delicate plants. In this case, use the grounds just as you'd use them to repel snails — sprinkle them around the plants you want to protect. The phytotoxic effect on the soil may be unavoidable here due to how much you'll need to use.

Use coffee grounds as worm food, with caution. If you participate in vermiculture (raising worms), you have a great opportunity to use up your coffee grounds. Worms love to eat coffee grounds, so feel free to add plenty to your worm bin or a worm-containing compost pile. Note, however, that coffee grounds should be part of a balanced diet: fruit and vegetable scraps, newspaper, leaves, and so on should accompany any coffee grounds you add. A diet of straight coffee grounds has been shown to kill earthworms.

Use grounds to discourage fungal infection. There is some evidence that coffee grounds can be used to prevent certain types of fungus from attacking your plants. A light sprinkling of coffee grounds may be able to prevent Fusarium, Pythium, and Sclerotinia species of fungi from taking root. Tomatoes, eggplants, and peppers are especially vulnerable to fungal infections, so coffee grounds make an especially good choice for these plants.