Siberian Iris

[Garden Manager]

I first became aware of this plant back this spring and was really taken by it. I have a couple of queries about it though as i not only want to propagate some from a friends garden but also move one in a customer's garden that they want to save to make way for a new extension.

I was wondering firstly when the best time to move the plants was and secondly when the best time to divide is and what technique i need to use Like i stated above these plants are relatively new to me so I have little to no experience of growing them. I do know that herbaceous irises are different in terms of cultivation to most other herbaceous plants.

Please advise.

[Garden Manager]

[Obelixx]

I have clumps of these growing round the edges of my unlined pond.  I shall be lifting mine this autumn and dividing them with a spade to cut through the roots.  Then it's simply a matter of replanting in well prepared ground so they get established in time to flower again next spring/early summer.

[ACE]

Now until late summer is the best time to divide them. Cut nice healthy rhisomes with a budding bit on, discard the old stuff. Moist but well drained  soil is best but they will tolerate sun or part shade.

Don't forget like most irises they like some of the rhizome above ground to bake a bit in the sun.

Obbelix you may have iris ensata as that prefers really a nice wet spot.

[Palustris]

Claire Austin (who writted the book about Iris and sells a few ) advised us not to split our clumps into too small pieces as Iris sibirica does not flower until you get a reasonable sized climp. shame really as in the middle of one of ours is a totally different coloured one and I would love to get it out and grow it on.

[Obelixx]

Mine is definitely sibirica.  I brought a clump from our garden in Harrow and it ahs survived all sorts of dreadful winters, wet summers and occasional heatwaves.

I do let the clump get big before dividing and I don't make the new clumps too small.  It's growing a few inches higher than the pond's winter water level and seems very happy, although this current drought is maing a few of its leaves crispy.

[campanula]

iris sibirica is a toughie and will happily grow in wet or dry soil. I will be splitting a few of mine but not till the end of August.

[Garden Manager]

Thanks for the replies.

Useful to know that they can be moved or divided pretty soon. Might be having to do just that

[GrannieAnnie]

Interesting= aftr googling siberian iris it looks like what I thought I was growing as Japanese Iris is actually Siberian iris. ::)

Anyway, what I learned with ours is: plant one clump in full sun and another in part shade and you'll have them blooming at different times, mine bloom for a month that way and isn't a clump of blue a treat to the eyee!

[Garden Manager]

One tip for growing siberian iris that i have recently picked up is, dont grow it near any of the more vigourous crocosmias (montbretia). The leaves are near identical and its difficult to get rid of the crocosmia without pulling up the iris instead!