Hill, one of football's most influential figures, died in December 2015 aged 87.
The garden will be officially opened before the Sky Blues' final home game of the season against Sheffield United on Saturday, 30 April.
The memorial will have a specially-carved plaque in tribute to Hill and some of his ashes will be scattered.
"This is the last journey - I'm sure we will have a lot of people wanting to pay their respects to Jimmy," former city chairman Joe Elliot told BBC Coventry and Warwickshire.
"People will be able to have their plaques and scatter their ashes in the Jimmy Hill Garden - it will be for supporters.
"But Jimmy will have the centrepiece - it will look fantastic."
Hill, who had played nearly 300 games for Fulham in his career, helped end the maximum wage for players as chairman of the Professional Footballers' Association.
He had a six-year stint as Coventry manager in the 1960s before moving into broadcasting in 1968 after guiding the club into the First Division for the first time.
Hill went on to present more than 600 episodes of Match of the Day before returning to the Sky Blues as chairman.
It was during his memorial service at Coventry Cathedral that Hill's widow, Bryony, suggested the idea of returning some of his ashes to the city.
"So many people come to the memorial garden and now it's going to be doubled in size," Elliot said.
"There is part of Jimmy Hill coming back to the city he loved."
A memorial garden honouring ex-Coventry City manager and chairman Jimmy Hill is to be created at the Ricoh Arena.