Among gardeners, aphids are one of the most hated of all insects, so learning how to kill aphids is going to be in order for anyone who wants pest-free plants. Aphids aren’t fussy! They attack all types of plants, from houseplants to outdoor flowers, vegetables and fruits. And, when they arrive they don’t appear one at a time, they swarm full force into the garden and can attack many different kinds of plants at the same time. They also have the ability to damage leaves, causing them to curl up, and then they hide in the curls so you cannot see them.