Details of the ambitious project were revealed as Suffolk Coastal District Council submitted an application for funding to the Heritage Lottery Fund's (HLF's) Parks for People programme.
The aim is to transform the 3ha of Cliff, Town Hall and Spa Gardens, using lighting, sculpture and diverse planting.
A team from The Landscape Partnership's Suffolk office has been working on the project with landscape architects and conservation officers from the local authority.
Landscape architect Nick Bunker said the gardens had lost their cohesion over time as extra land had been added to the site, which runs for 1km along the coast.
"The gardens have been built up from their beginnings in 1901 to later additions in the 1950s," Bunker explained.
"The council has these piecemeal bits which have been donated over the years and it is a mosaic that doesn't make any sense.
"We've also lost a lot of the original vistas in the gardens and we need to sort that out."
Signs and information boards are included in the plans and aim to help visitors appreciate the gardens' wildlife, geology and history.
Proposals include an open-air performance space next to the Spa Pavilion, paths linking the gardens to the national cycle route and informal play areas for children.
Bunker added that the site's microclimate allowed for a wider range of planting.
He said: "It is an unusual spot because of its aspect, which is quite sheltered. That means we can grow things we wouldn't be able to in the rest of the county. It is quite Mediterranean, so we can be creative within reason."
Some contemporary elements will feature in the gardens, although the focus is on its heritage aspects as part of the HLF bid. The council will find out if it has been successful in June, at which stage widespread consultation will begin on the refurbishment project.