L ast week someone from Thames Water turned up to say we were using more than the average amount of water. I tried to explain that we have small children; I spend my life doing laundry and baths are one of my few vices. And no, we don’t have a car to wash or use a hose in the garden. The visitor then presented us with a small hourglass with a suction pad attached. Now, each morning, my husband and I emerge from the shower, crowing that we managed to brush our teeth and wash and condition our hair in under four minutes. I’ve never been hugely rash with watering the garden – as a result of my climate anxiety and, frankly, laziness. I’m on trend. Resilient, drought-tolerant and water-conscious gardens have been appearing in one form or another on Main Avenue at the RHS Chelsea flower show for the past decade (even though you invariably see volunteers frantically watering things most mornings of the show).…