Dividing gives us new plants from old, which is always good, and it also revives revives old clumps. You can favour varieties that have coped well with our increasingly erratic weather or simply create more of your favourites.

As with a lot of new planting, it’s worth dividing plants that have finished flowering but are still active just now. The soil is warm enough to let roots grow and the transplants get established.

Start by confirming that this is the right time to divide your selected species. After all, some like later summer flowering perennials that include Michaelmas Daisies and Leucanthemums should be left till next spring.

You must lift the whole clump: a fork does much less damage than a spade. And, as with all planting and replanting, give the clump a good soak because it’s easier to prise roots out of wet soil without breaking them.

Work round the clump, sinking the fork as deeply as possible, moving the fork towards the clump as well as away from it while digging.

Having dug up the whole clump, wash away the soil to see its shape and assess the best way for dividing. Some readily pull apart, others, like hybrid Hellebores, may need an old pruning saw or big kitchen knife to cut into large chunks, making sure each has several growing shoots.

On the other hand, bearded irises are a little different. When lifting, be sure to dig deeply enough to keep the roots growing beneath the rhizomes. Don’t cut the rhizomes but tease individual ones apart, discarding the soft and the withered.

If replanting in the same spot add home made compost or some all purpose fertiliser to help with re-establishment. Cut across the fan of iris leaves attached to vigorous rhizomes, reducing leaf length by half. This reduces transpiration of water from the leaves so makes the whole process less stressful for the establishing root system. Keep the transplant well watered during a dry spell.

You might need to divide some species, not necessarily to get more plants but to prevent them from spreading beyond their allotted space. I love overly enthusiastic hardy geraniums but must keep on top of them.

Encourage abundant flowering by digging up as much of a clump as possible. These are good candidates for the classic two forks back to back approach to tear and prise the clump apart. Select the healthiest looking sections for replanting. Some like ‘Johnson’s Blue’, Geranium nodosum and G. sanguineum have rhizomes, others like Geranium macrorrhizum have snaking, fleshy roots. Make sure, in both cases, that you take at least a couple of leafy shoots attached to a generous amount of root. Trim off dead and elderly leaves but retain fresh ones.

The Herald: Anemone Prinze HeinrichAnemone Prinze Heinrich (Image: free)

Plant of the week

Anemone huphensis ‘Prinz Heinrich’ is a Japanese anemone with semi double flowers in a shade of deep pink that is strong enough to shine out despite weakening sun and often grey skies. It is hardy but, like most Japanese anemones, prefers damper but well drained soil and partial shade.

Japanese anemones may take a couple of years to fully establish and young growth in spring is vulnerable to slugs and snails but, if happy, clumps will spread.