Each must have a total of 17 syllables in three lines of five, seven and five syllables respectively. They will be judged by people with a vested interest in Guyton St, and the winner will receive $100.
The winner will be announced on September 2 and the haiku will initially be displayed in Paige's Book Gallery.
It will be the first poem in the Guyton St poetry trail which will stretch from the Heads Rd Cemetery to the Whanganui River, Goodge said, with poems on buildings, in windows and on other structures.
All will be written by Whanganui people or have a strong link to Whanganui. A few words from James K Baxter, a piece by Airini Beautrais and a poem from sculptor Joan Morrell are all likely.
The competition-winning haiku will be an original and unpublished addition.
"Wouldn't it be nice to have an original new piece to put up?" Goodge said.
Entries can be delivered to Paige's Book Gallery in Guyton St or emailed to hello@paigesbooks.com before the competition closes at 5pm on Friday, August 27.