Cayenne pepper spray is one of the simplest, most natural ways to protect your garden from bugs, and it works because pests hate the intense heat and strong scent. . When you mix cayenne with water — often paired with a little dish soap to help it stick to the leaves — you create a spicy barrier that keeps insects like aphids, beetles, caterpillars, and even some small animals from chewing through your plants. . The spray doesn’t harm the plant at all; instead, it creates an environment pests do