Black tip (specific to Plumeria obtusa in cooler climates)
In early spring, at the first signs of new growth, a bacterial problem commonly known as “black tip” can appear. This causes die back of the new growth but creates more branches.
“Black tip” rarely kills the tree.
The cause of the “black tip” fungus is low spring temperatures combined with high humidity. By late spring when temperatures increase the “black tip” disappears.
To try and reduce its unsightly appearance seaweed extract liquid fertilisers can help. Begin foliar spraying at the first signs of new growth prior to the first signs of the “black tip” fungus and then spray once a week until early summer.