Rejuvenating Iris sibirica29th March 2018 • In The Garden • Stephanie Donaldson
I love iris sibirica. It is an undemanding plant that will grow in most soils and has fine grass-like foliage that is a perfect foil to its delicate flowers that appear in May. Unlike the flag iris, it doesn’t mind a bit of shade, its foliage looks good long after it has finished flowering (provided you give it some support), it turns a lovely bronze colour in autumn and remains looking good through most of the winter.
In the process of doing the spring tidy, I have been cutting back the remaining tatty foliage on these plants and noticed that the oldest plants have developed a hollow centre. This happens once the plants have reached three or four years old and means it is time to split them to stop them taking up more than their allotted space in the border and to improve flowering – a plant with a hollow centre will only flower around the edges.
Iris sibirica requires a bit of muscle to prise it out of the ground, but by digging round it with a spade and then loosening it with a fork, I did manage to dig it up. The central part of the plant was discarded and the rest divided into several new plants. After forking over the soil where it had been growing I added some compost and replanted one of the divisions, giving it a good water and adding a mulch. The other plants have been given to friends to spread the happiness.