I don't know where scale originate, honestly. My (lemon) treelet arrived with it, but it was a gift, and I was hardly going to complain about it, because of that. Yes I scraped the scale off my lemons stems and leaf when it had only 4 branches, and into the dirt around it, though I did throw away the leaves I pulled off the tree that had too many scale on it to get off. Maybe I was lucky, or maybe they're lurking around my lemon, just waiting to visit it again?
I have heard that oil sprays suffocate scale, but I've also killed house plants (gardenia) trying to destroy mealy-bug infestations with fruit-tree dormant oil spray, I'm not sure if that works well on all plants, my gardenias definitely didn't appreciated it:(
Never tried Neem oil or insecticide; but have heard good things about it, and I prefer natural insecticides, so should this problem ever arise again for me, I'll consider it, and definitely the coffee grounds, -maybe the easiest thing of all.
(I have a mental image of giving the plumies coffee and them suddenly "taking off" with several feet of caffeinated growth..eek!)
Thanks for all the suggestions, will file them away, and I hope one or a combination of several wil save your plumeria, Vanan.
