My plumeria has not bloomed this year although I fertilize it regularly. The foliage is massive and beautiful, but no blooms. I have 4 . 2 are blooming now. 2 have no signs of buds. What is wrong

To much nitrogen causes green growth and no bloom's and sometimes plumerias will build a root system first in order to support the blooms so they won't bloom till that's done. Have a great day

The problem is that you are most likely over-fertilizing. Fertilizing more that twice a season tends to stimulate foliar growth at the expense of blooming. I'd recommend fertilizing not more than twice a season to improve blooming results.

I agree with Buddy.