"If you look at late 19th century photographs or sketches of Delhi, it is empty and treeless. It's a historical fact that the city's greenery has come with the development of urban settlements... My favourite Delhi garden is Sundar Nursery because there are always new trees to discover there" – Swapna Liddle and Madhulika Liddle, co-authors of Gardens of Delhi talk to Manjula Narayan about the capital's wonderful green oases from Lodhi Garden and Qudsia Bagh to Buddha Jayanti Park and The Garden of Five Senses, among many others.