19+ White Spots On Plumeria Leaves. I got my 1st plumeria cutting last year and it has grown like a weed (indoor, potted). Examine the leaves of the plumeria for black and white discolorations.
Thankfully, identifying and effectively treating the cause is easier than you think.
The white spots are actually tiny insects called scale. Spa stones and leaves on black background. Hitting the leafs with a hose, top and bottom will knock down a lot of the bugs. Look behind the leaf for them, might need a magnifying glass depending on how good your eyes are.