The capital comes alive in the summer. From the Serpentine’s glittering June party to the Royal Academy’s must-bag-an-invite summer bash, and onto Wimbledon, Henley and Silverstone — the city’s movers, shakers and power brokers have a packed calendar of places to see and be seen. Quaintly, it all kicks off with a gardening show. Yes, RHS Chelsea Flower Show is back.