Dividing Sisyrinchium

The ideal time to divide most perennials is after flowering - except for late blooming ones which should be left until spring.

Some perennials positively need dividing after flowering as the flower stalks and the part of the plant that produced them die off and look ugly.

Sisyrinchium (Pig Root or Silk Flower) are prime examples as are other members of the Iris family.

I've been dividing my Sisyrinchium Aunt May today as the latest round of flowering has come to an end. Hopefully they'll now flower again later in the autumn.

Here's how I go about it step-by-step:

After flowering the plants can look a little messy with dead, black leaves and flower stems.

I dig up the whole clump and shake off as much soil as I can and then I weed out around where the plants have come out. It's surprising how many dandelions seed amongst the clumps.

I pull the separate "fans" of leaves apart. Irises need tugging and cutting to divide. The fresh fand (left hand side) are prepared by striping off the old, blackened outer leaves. Don't expect very much root on these fans - that's not a problem.

The fans with old flower stems (right hand side) are no use, except if you want to save some seed. (The variegated leaves aren't carried forward in the seed so you'll get plain green seedlings).

I don't shorten the leaves of Sisyrinchium, like you might on other plants, as this will cause ugly brown tips on the new leaves.

Nomrally I'd liven up the soil with some garden compost and fertiliser before replanting the new fans but the soil was quite rich so I just added a little blood fish and bone lightly raked into the soil.

The fresh fans of Sisyrhinchium are planted at around 2-3in depth and the soil is firmed around.

Water the ground well and remember to water each day unless there's plenty of rain on that day.

I may have to go over the plants and remove the odd dead leaf until the plants are growing away strongly.

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