Don't Throw Out Coffee Grounds, Put Them On Your Patio

There are few bigger or more common nuisances than pests like ants. They tend to arrive in the spring and summer, putting a damper on our excitement around warmer, brighter days. There are solutions to this problem, but some of the more established go-to fixes involve harsh chemicals that aren't great for the environment and that you may not want to spray around your kids and pets. Luckily, there are eco-friendly — and free — ways to send pests packing, and these involve looking to your own pantry or food waste. Ant infestation prevention is one of the key ways you can repurpose food scraps to avoid waste, and one of the most effective options might just be coffee grounds. A safe, sustainable, cost-free approach for getting rid of ants might sound too good to be true — but here's how this can indeed work.

Coffee grounds have been found to repel ants. The University of Science Malaysia studied the effects of Arabica, Liberica, and Canephora coffees on ghost ants, big-headed ants, and pharaoh ants. Not only are Arabica beans the most common type and therefore likely what you'll have grounds from at home, it was also the most effective at killing ants. Overall, though, across coffee varieties and ant types, the study found that coffee grounds are better at repelling than killing these insects. You'll see the best results utilizing coffee grounds before you have an infestation rather than trying to stop an infestation with them.

While some results have been seen applying coffee grounds to ant hills or places where they've already shown up, grounds are more reliable in avoiding an ant problem before it starts. Ant trails form when an ant finds a food source and creates an invisible map of pheromones to it for other ants to follow. A line of coffee grounds breaks this trail. It's important they are fresh — once the intensity of their aromas fades, so does their ant trail-busting power.

Coffee grounds are one of the best, eco-friendliest ways to keep ants away, but you do have to consider where you want to sprinkle them. You may not love the idea of creating what looks like lines of dirt around your kitchen, for example — but coffee grounds are perfect for outdoor spaces like your patio. Simply let your just-used grounds cool and dust them in a barrier around your patio, or in areas you've experienced issues in the past.

You can create the same kind of boundary in your garden, but more carefully placed. Ants can actually help your garden thrive, and coffee grounds have both nitrogen — which can be good for soil but only in restrained amounts — and caffeine, which isn't great for plants. Only use grounds sparingly, where you've had real ant issues. That nitrogen makes coffee grounds effective absorbers for unpleasant aromas, handy in spots like the garage — they can keep ants away there, too, to boot.