Question

what are the fair pledges that the poet refers to? why does he call them fair pledges​

Answer 1

A pledge means a promise. When the poet says 'Fair pledges of a fruitful tree', he is connecting the blossoms to being the promise of a fruitful tree. A promise is made keeping the future in mind. So, the blossoms are making some kind of a promise to the trees. ... Hence blossoms are 'pledges' of a fruit-bearing tree.

hope it will help Uh dear..