A pruning poem is a poem that uses rhyme

Rhyme

A rhyme is a repetition of similar sounds in two or more words and is most often used in poetry and songs. The word "rhyme" may also refer to a short poem, such as a rhyming couplet or other brief rhyming poem such as nursery rhymes.-Etymology:...

s that are prunings of each other.

Each rhyme word is one letter shorter than the rhyme word before. Otherwise, they are the same word. While it is possible to write a pruning poem in couplet

Couplet

A couplet is a pair of lines of meter in poetry. It usually consists of two lines that rhyme and have the same meter.While traditionally couplets rhyme, not all do. A poem may use white space to mark out couplets if they do not rhyme. Couplets with a meter of iambic pentameter are called heroic...

s or longer, it is most effective when the reader sees the pruning on the page. Thus, George Herbert

George Herbert

George Herbert was a Welsh born English poet, orator and Anglican priest.Being born into an artistic and wealthy family, he received a good education that led to his holding prominent positions at Cambridge University and Parliament. As a student at Trinity College, Cambridge, Herbert excelled in...

, who conducted many formal experiments in verse, writes Paradise as a pruning poem.

What open force, or hidden charm

Can blast my fruit, or bring me harm

While the inclosure is thine arms?

Pruning could be accomplished by cutting terminal as well as initial letters, but initial position pruning is the more common and noticeable.