In its first publication of such a document, the OSS has set out its objectives for dealing with the struggle to protect spaces threatened by development.
The five-year plan includes aims that meet the OSS's mission to protect, increase, enhance and champion the common land, village greens, open spaces and public rights of way in England and Wales.
OSS general secretary Kate Ashbrook said: "We've been operating for 143 years but we've never set out what we do in a formal way like this. We need to make sure we all know what our priorities are."
New aspirations in the strategy cover points such as running training days and seminars for government departments and local authorities, appointing local "correspondents" to cover every authority area and encouraging local planning authorities to require dedication of open spaces as greens in development schemes.
The HTA-run Greening the UK campaign shares similar aims in terms of its work and organiser Mark Glover said he supported the strategic plan. He said: "We're supportive of what the OSS is doing but also we need to recognise that the space covered by private developments and the street scene is huge, particularly in urban areas."
"We would welcome anything that brings greater planting, however this strategy is only tackling part of the problem; it's not a whole solution."