Late summer is the perfect time to plant irises. Here's how to care for them

Irises are essential spring and early summer flowers that are grown from bulbs, offsets and rhizomes in a bewildering number of forms. They have six petals – three upright and three that curve downwards (standards and falls, respectively) – stylised as the fleur-de-lis symbol of France. They thrive in any reasonable garden soil that is well-drained and in the sun.

The bearded irises (main image), from rhizomes, have a “beard” of fleshy projections on their lower falls. They are bold, spectacular, hugely popular border flowers in sumptuous colours for early summer. Theoretically, the ideal time to plant or divide is straight after flowering – as the flowers for next year are initiated in late summer. However, they can be successfully planted at any season, and traditionally late summer