Divide your bearded irises in August, says Emilie Griffin

Bearded irises with rhizomes (this can be recognised as they have fleshy stems at soil level) are divided about six weeks after flowering, usually mid-August. This gives the plants sufficient time to produce new growth for the following season before they’re struck by the chilly autumn and winter weather.

Divide your bearded iris following this step-by-step

Lift the whole clump carefully with a garden fork, shaking the roots free of soil. Then gently break the clumps into manageable portions

With secateurs cut the top half of the leaves off and cut sections of new rhizomes (lighter in colour) from the pieces with shoots & roots attached

Trim the roots by one third and then dust the rhizomes with yellow sulphur to prevent rotting. Replant each section approximately 1ft (30cm) apart

Here are nine of my favourite varieties of bearded iris:

I. ‘Ancilla’

I. ‘Annabel Jane’

I. ‘Baby Blessed’

I. ‘Blue-eyed Brunette’

I. ‘Carnaby’

I. ‘Dark Vader’

I. ‘Edith Wolford’

I. ‘Flamenco’

I. ‘Jennifer Rebecca’