Frillibet is the frilliest hydrangea we have: it was even frilly when it first flowered in Fillan’s pot (left). The colour then was a light greyed pink. Cuttings rooted here were lilac when they first flowered in pots (above, right). Planted out in a bed acidified with ferrous sulphate, the original plant flowered in a range of choice shades from violet to sky blue, pictured below. In later seasons, all the flowers were sky blue. The progress from colourless floret to autumnal reversal is shown in part 2, next.