Hi Sarah-

I'm so sorry to hear about your spittlebug infestation! They can be frustrating little critters. Spittlebugs create a frothy, bubbly mass as they feed on plants like ornamental grasses, roses, chysanthemums, clover, strawberries, herbs, and the list goes on. Although they create a bit of a mess, usually spittlebug feeding doesn't damage the plant. That being said, if there are too many spittlebugs, their feeding can cause leaves to lose their shape and may stunt plant growth. 

When they are in smaller numbers, managing them is unnecessary as plant damage is very minimal. When they appear in large numbers, management revolves either removing their food source (weeds or other plants that they are gathering on) or removing them either by hand or spraying them with a strong blast of water. The white foam that you see protects the spittlebugs from pesticides, however a strong blast of water will send them sailing. More information can be found below:

https://pnwhandbooks.org/insect/hort/landscape/common/landscape-spittlebug-froghopper

https://extension.umn.edu/yard-and-garden-insects/spittlebugs

I hope this helps! Happy gardening!