The cornflower that named the colour. Dense, fully double, ruffled heads in an electric azure that looks lit from inside, on silver-green stems. If you grow only one cornflower it should be this one.

It is a genuine cut-and-come-again plant. The more you take, the more it makes, and a short row will keep a jug filled from early summer to the frosts. Stop cutting for a fortnight and it sets seed and shuts down, which is the commonest way people lose a cornflower crop in July.

Two honest notes. The doubling that makes the flower substantial also crowds the centre, so it is less use to bees than the single wild form; if pollinators are the priority, grow some wild cornflower alongside it. And at this height the stems lean after heavy rain unless there is something to hold them, so run a net or some twiggy sticks through the row early rather than after it has gone over. Self-sown seedlings drift back towards smaller, simpler flowers within a couple of generations.