The abundant verdure that’s a signature of the Delhi aesthetic—especially the parts that run along a north-south meridian, including the planned city at its nucleus—is facing a threat. Seven ageing but genteel colonies on the southern fringes of Lutyens’ Delhi are encumbered with fancy new development projects. All of them boast lush green vegetation, and ‘redevelopment’ means sacrificing 16,500 full-grown trees.