Primroses and polyanthuses can be divided either immediately after flowering, which is probably in May, or in early autumn (September or October). If your winters are particularly severe, you'll probably get better results by dividing in May, as this will allow your plants to re-establish before winter hits.

How do you split Polyanthus?

Lift the plant with a fork, taking enough soil to avoid damaging the roots. Shake off as much soil as possible, washing it off if necessary. Tease the roots apart and cut out large well-rooted crowns for replanting. Plant the small pieces also, - you will probably be lucky !

What time of year do you divide plants?

Plants should be divided when they're dormant, in late autumn or early spring. Fleshy-rooted perennials, such as paeonies, should be left until the end of their dormant season in late spring, before being divided.