Q. My rosemary plant has white foamy droplets on the stems. I can spray them away when I water with a hose but they return. They do not seem to be harming the plant but what is it?
|Spittlebugs are common on rosemary and live within the spittle for protection|
A. The white foamy droplets are called spittlebugs and common on rosemary. They suck plant juices and are buried inside the spittle for protection. They can be knocked off the plant with a strong stream of water from a hose but they return quickly.
They are usually more of a nuisance than a problem unless you are growing rosemary as an herb. They can multiply and become a problem in the future so keep an eye on them.
Neem oil and horticultural oils will give some control of spittlebugs when sprayed directly on the plants. Spray a small section of the plant first to make sure the oils do not damage the rosemary.
Soap and water sprays wash the spittle off and leave these bugs unprotected. Follow this with an insecticide spray such as pyrethrum which protects the plant from becoming reinfected. This might need to be done several times, a few weeks apart, to get them back under control.