As – what I am assured by the Met Office is the last snowfall – drifts past the window, I’m resolutely preparing for warmer days. The dahlias that have successfully overwintered under the greenhouse bench have been disinterred from their dry compost and repotted as have their colourful new companions. Dahlias, I’ve decided, are rather like zinnias. Forget subtle shades and go for maximum color impact. This is especially true in our coastal garden where pale colours can look washed out in high summer.