Park managers must act like entrepreneurs but avoid jumping too fast into schemes such as trusts that could result in costly, catastrophic failure, sector leaders have urged.
GreenSpace chief executive Paul Bramhill told the UK Public Parks Summit hosted by the Heritage and Big Lottery Funds: "We are looking at funding models ever-more closely. Many people like the idea of trusts such as at Milton Keynes with sustainable long-term funding and we have worked on guidance on what you need to think about.
"But we don't want local authorities and others leaping into private trusts that aren't sustainable and don't take parks forward. Many are just mechanisms for moving costs elsewhere. We want to keep the strong link between parks and local authorities."
He told the summit: "We want to free up managers to think more as entrepreneurs and bring together potential funders with community groups, non-government bodies and elsewhere."
Land Trust director of operations Matthew Bradbury said: "The elephant in the room with trusts is you need a multiplier of around 20 - £2m to £3m to set it up and £50m to make it sustainable. We have to make sure that people don't set up poor trusts that fail in the future."
Bradbury said the Land Trust is to launch a Green Space Income Toolkit early next year, aimed at local authorities, trusts and other groups that manage landscapes, to allow users to share best practice. It will signpost people to income streams.
The toolkit, called Prosperous Parks, will answer a range of frequently asked questions on income ideas such as sponsorship and events, concessions, agricultural income and advertising. It will also outline how to overcome legal, financial and practical hurdles and it will offer case studies.
Greenspace Scotland chief executive Julie Procter said: "We should never underestimate the power of evidence, statistics and numbers. But it's not just having that data, it's how you use it. A survey last year revealed a steep fall in park visits - a dramatic and stark wake-up call.
"In recession, people should use free parks more, but this reflects a change of attitude on the quality of the space. The results of cuts in staff and upkeep are being seen. We need to get people smarter on making explicit, and selling, parks' benefits."
Bute Park Restoration project manager Dr Julia Sas gave examples of how a £5.6m restoration of the 59ha Cardiff Park was used to ramp up revenue streams through feed-in tariffs, corporate hire and a gift and tea room that was featured on The Great British Bake Off.
"We need shock value - we always talk about what's the value we get from good-quality spaces, but I would like to see data on what's the long-term cost on society of low-quality spaces and no investment in our parks."
Peter Neal, Landscape architect and consultant.