The international celebration of landscape architecture runs throughout April, and showcases landscape architect-designed spaces around the world via social media. Both landscape professionals and members of the public will be asked to share pictures of their favourite landscapes.
Last year's campaign attracted photographs of children's playgrounds, rooftop gardens, ecoparks, tourist attractions and waterfront mega-schemes.
Farrer said: "No other profession combines the arts, humanities and sciences in the way that landscape architecture does. At its heart is the environment and our relationship with it. Both natural and urban landscapes form over generations through the interaction of natural and human processes. The landscape architect's job is to mediate that interaction.
"It demands the vision of a designer, underpinned by scientific and technical rigour. It has never been more urgently needed. This April I would urge all landscape professionals to get involved in World Landscape Architecture Month and highlight the magnificent projects and work we have in the UK."
More information about this year's events is available on the website of the American Society of Landscape Architects.