Common Yard Pests That Aren't Bothered By Coffee Grounds

If there are regular coffee drinkers in your home, chances are that you have a lot of leftover coffee grounds to use around your home. Many people attempt to reuse coffee grounds around their gardens for a variety of purposes, including as compost, a fertilizer for soil, and even pest control. It's the latter use that can often evoke some confusion. While there's some scientific evidence to support the use of coffee grounds in controlling certain pests, rodents and deer may not be bothered by this tactic.

Since coffee grounds are often thrown away after the brewing process, reusing them can seem like a great way to reduce waste. Also, given the drastic increase in coffee prices, this could arguably be a good way to stretch the money you spend, too. Used coffee grounds contain nitrogen, phenolic acid, and lipids, and they still retain some of their scent. These properties are often sought after for possible natural pest deterrents, although evidence supporting most of these methods is lacking.

What we do know is that coffee grounds can help control snail and slug problems in your yard when they're used as a DIY spray or a soil amendment. To create a pest control spray for these slugs and snails, Oregon State University recommends using a 2 to 1 ratio of freshly brewed coffee and water. Sprinkling coffee grounds in garden soil might also help deter these pests to some degree. Some blogs even suggest using coffee grounds for deer and rodents, but these are largely unfounded theories.

While coffee grounds may get rid of slugs in the garden as well as snails, the same cannot be said of rodents and deer. Some people claim that used coffee grounds may deter such pests because of their strong odors. As such, you might be wondering whether sprinkling coffee grounds around your garden beds might prevent mice, rats, squirrels, and deer from messing with your plants. There are anecdotal reports of this method working to some degree. The problem is there just isn't enough evidence to support using coffee grounds as a definitive solution for a deer or rodent problem in your yard.

If you happen to have some used coffee grounds on hand, you could see if these might prevent pests around your yard. You shouldn't invest too much money or hope in this method, though. Instead, removing food sources are among some of the more worthwhile techniques to help deter deer and rodents from your outdoor spaces. Pet food, bird seed, and garbage are common food sources rodents might seek, so removing these items can help. Deer can be trickier to control because of the wide variety of plant items they consume. Fencing of at least 8 feet tall helps prevent deer from climbing over. Just make sure you're avoiding the worst deer fence materials and opt for more effective materials, such as woven wire or wood panels.