Landscape designer David Seiter champions the ecological and aesthetic benefits of informal plants - weeds - in urban space, and catalogues the uses and cultural significance of New York's native flora.

In the second of a series of interviews with visual artists, Emily Henretta discusses how the process of collage and the experience of cities inform each other.

In the first of a series of interviews with visual artists, Roberto Mollá discusses the influence of architecture and the urban environment on his work.

An illustrated slide show about tidal in-stream energy conversion and what New Yorkers need to know about its potential to redraw the map of power generation in the city.