Jo Watkins, president of the institute, said: "In times of recession there is a need to be innovative and resourceful. These awards capture the zeitgeist.
"Faced with a challenging economy and increasing social and environmental pressures, the benefits of careful intervention in the landscape become even more relevant and frugal innovation moves higher up the agenda."
Sarah Gaventa, a director of CABE, which is to close following budget cuts, said the imminent closure of the body was very sad. "It's still very hard to believe that most of the team will be leaving CABE by Christmas and we will no longer be working with so many of you here today," said Gaventa, who received an honorary fellowship at the event.
"It has been a pleasure and honour to work in the sector and we are grateful for your contribution and support over the years. We need you here to keep telling the story of why landscape matters."
Among a host of gongs during the evening was the president's award for the "best project of the year", often seen as an indicator of trends in landscape design.
The Landscape Partnership won the title for a sustainable drainage design-and-adoption guide for Cambridge City Council. It is a landscape-led look at how the city can tackle sustainable urban drainage and looks at gradients, soil types and flood risks.
"It sets the standard for innovative intervention in the landscape and is a model for others to follow," said Watkins. "Sustainable urban drainage is a great example of frugal yet appropriate development."
Student entrants competed for the Future Vision award, which challenged them to find ideas for making villages, towns and cities better places to live.