From a flower-filled moat at the Tower of London to a rooftop community garden on the Old Kent Road, the work of the landscape designer, horticulturist and educator Nigel Dunnett, who has died aged 63 from cancer, showed how urban landscapes could be visually dramatic, ecologically rich and experientially uplifting. Dunnett’s deep plant knowledge, design acumen and advocacy of biodiversity helped change how cities, institutions and public audiences understand the role of landscaping and naturalistic planting. As a pioneer of ecological and sustainable approaches to gardens, landscapes and public spaces, he saw planting not just as a cosmetic afterthought but as a living, evolving and inspiring part of urban life. His Superbloom project for Queen Elizabeth II’s platinum jubilee in 2022 involved 20m carefully selected seeds, including poppies, corn marigolds and cornflowers, sown in the vast moat that girdles the Tower of London.…