"Nobody's going to throw flowers at someone who made a lot of money, " Mr. Diller says.

WSJ: No. 2 Diller Says Investors Benefited

That is a lot of prime London real estate populated by some very privileged trees and flowers - and, in the case of Richmond, red and fallow deer.

BBC: Common people: London's green spaces

Any colourful flowers are good, and the caterpillars of a lot of British butterflies are grass eaters - so allowing native species of grass to grow a bit longer in the summer will help.

BBC: Butterflies hit by damp summers