Frothy foam
By Homely59
Wiltshire,
United Kingdom 
I have white frothy foam on a climbing rose and have just seen it is on my lavender in a pot several feet away, can you please tell me what it is and is there anything in the house that would get rid of it, i hate to use chemicals unless i have no choice. Regards Sue
2 Jun, 2008
Answers
The good old RHS confirms what Caz13 says:
http://www.rhs.org.uk/advice/profiles0601/cuckoo_spit.asp
2 Jun, 2008
The bubbles are caused as they feed on the fresh young sappy growth. I flick the plant so as to disslodge the bubbles so the birds can see and eat the bugs.
As Caz and UKslim say's they dont harm the plant I also hose them off.
2 Jun, 2008
'Cuckoo spit' probably. Nothing to do with cuckoos, but secreted by insects called froghoppers. You can wash it off with a hose, the insects don't really harm the plant, so there's no need to use insecticide
2 Jun, 2008