Today while looking at my Salvia bush, I found it covered in these white round things. What are they? Their shape and size isn't regular, ranging from a couple mm to a cm in diameter and generally round. Some completely surround the stem while others are only on one side.
I am at the north end of California's San Joaquin valley
They look like spittlebugs. They produce a bubbly spit-like substance around themselves for protection from heat, predators, etc. Your reply to me question seems to confirm this. Apparently, they can be plant-sucking pests, but I've only seen them on rare occasions in small numbers before (mostly in my childhood on giant garden weeds), and the plants didn't seem threatened (but weeds are resilient, and I was a child).
