Under the proposal, two part-time rangers would be employed to patrol the garden during weekends, public holidays and other busy periods.
Funding for the initiative has been included in the council's draft 2019-20 annual plan, subject to public consultation.
The rangers initiative followed a string of high-profile incidents involving men performing lewd acts in the garden last year.
Botanic garden team leader Alan Matchett said the incidents were a "major consideration" behind the rangers proposal.
At present, just one council employee worked at the garden over weekends, but their focus was on operational issues - including watering plants and emptying rubbish bins, Mr Matchett said.
Having a ranger on duty at the same time would improve staff safety, as well as providing a point of contact with members of the public, he said.
"Without council staff present during the weekend, there's a gap in our service."
However, the rangers would not be expected to tackle questionable behaviour at the garden head-on.
Instead, they would be in direct contact with the council's security contractor, police and other council staff, Mr Matchett said.
They would also be able to alert other members of the public to any problems and keep them away, he said.
"Their own safety is paramount, as well as members of the public."
Council parks and recreation group manager Robert West said the proposal was for 1.2 full-time equivalent (FTE) positions to be created, costing $85,000 per year.
The proposal came after considering what other gardens in Christchurch, Wellington and Auckland already did, he said.
The council was "always mindful" of security issues and staff safety, and in the garden had "a relatively small staff group across a large site".
But the rangers would be tasked with more than just staff safety, he said.
"Really it's someone who would be walking around the gardens having a customer focus - it might be providing some education for visitors, it might be providing information for visitors about the garden, but also at the same time being mindful of security issues."
