Westminster City Council is re-structuring in a move towards a model known as "strategic commissioning", which experts fear could lead to a reduction in horticultural skills across the country.
With the Government expected to freeze local authority grants from 2011/12, leading to real-term cuts, the pressure is on.
According to Local Government Association chairman Margaret Eaton, the squeeze is likely to continue for several years.
"But ministers should realise that they can only keep on squeezing out savings for so long and that further efficiencies will not solve the pressures caused by cuts in funding," she warned.
At Westminster council - which received 18 Green Flag Awards this year - 500 "vulnerability letters" have already been sent out to staff and official redundancies will be made on 1 October, when the new structure comes into force.
The main decision-making for the council's services will be done by a "commissioning board".
Below the commissioning board is a series of nine "delivery units", which differ from a department in that they do not set their own targets. These include Sports & Leisure and Street Management units.
However, parks activity does not come under these units but is being moved into a "procurement and contract management strategic support unit".
Westminster City Council director of human resources Graham White told HW he anticipated about 200 people would actually go, with a further 70 posts already vacant.
He added that the new model was being implemented because of government pressure for more joined-up working, as well as the financial crisis. The move is thought to safe £15m.
"It is clear that public spending will come under pressure for a considerable number of years," White said.
"We have reserves, but we are wise enough to know when we start tapping into reserves they won't last forever. We know in future there will be less ability to generate income and that funding will be chiselled away by government."
The council lost around £12m in the Icelandic banks crash, although it expects to see that return, and income from planning has dried up as development takes a nose-dive.
Continental Landscapes currently works in partnership with the local authority parks department to manage green spaces, but White said the change to strategic commissioning would lead to a shift in the way work was carried out.
"In the past we would have negotiated how we'd deliver a service, for example by specifying our partner cut the grass in all our parks three times a week, whereas now we consider the outcome of a service," he said. "We would commission for our parks to be kept to a particular standard and the provision is a matter for the provider."
Westminster's principal parks and open spaces manager John Tweddle told HW it meant a "reality check" for the whole council.
He continued: "Where Westminster is today, others will be tomorrow. This is a drive from government that we do things differently now."