Q: I have noticed white, frothy, wet masses around the stems of my penstemon plants. What causes this?
A: You have spittlebugs on your plants. The young spittlebugs attach themselves in a joint between leaf and stem and suck out plant sap. The sap is excreted in a bubbly mass around themselves, giving protection from predators and the sun. The can also be found in lawn grass and on the tips of pine limbs.
I see spittle masses on many garden plants, including on weeds. Insecticidal soap will kill them. You can also simply wash them off the plant …… or pick them out and mash between your fingertips.
Froth on plant stem