HARDLY surprising but a plant with Siberian in its name is a pretty tough customer.

Reader, and regular CP contributor, Anne Grant, contacted me wondering if splitting her tousled and congested mop of Siberian iris growth would cause terminal damage.

She bought it as a small potted plant from a Women’s Institute market five years ago.

“As you can see it is now a large clump and needs splitting up into three or four plants,” she says.

“I like this plant because it blooms at a time of year when almost all else in the garden has shut down for winter.

“The first flower appeared on my iris on December 1. It has blossomed every day since and at its peak had ten flowering spikes. A welcome sight to brighten dull days.

“As it flowers at the opposite time of year to the more showy bearded iris, when is the ideal time to lift and split the Siberian variety?

“How do I do this without damaging it? ”

Well, Anne, to keep the iris blooming beautiful, it should be divided whenever the plant outgrows its boundaries, or when the middle of the clump begins to die down.

Clumps of Siberian iris should be divided after the plant has finished blooming.

Prepare new sites for the divisions by putting a thick layer of compost in the holes and some slow release fertiliser like blood, fish and bone.

Dig up the plant with a spade well away from the clump, working all the way around the perimeter and loosening the roots by rocking them.

Pull the clump apart at its natural divisions which will be apparent.

Dealing with this tough cookie may need a sharp knife, but don't be greedy — leave a large root on each clump.

Cut the foliage back to about six inches, plant in the desired spot, water-in and mulch.

And next year the garden will be decorated with lots of these pastel beauties.