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Dividing Irises

janinerjaniner Posts: 66
Hi everyone. 
We moved into our house in Nov 21. 
We have an iris bed down the side of the house. I've read that you need to divide them every few years. How do I know if I should do this? 
Thanks

Posts

  • A photo would be appreciated. 
    Southampton 
  • janinerjaniner Posts: 66
    I will take one in the morning and post. Thank you!
  • FairygirlFairygirl Posts: 55,117
    They get less productive over time, and spread in roughly a circle, leaving a dead middle section. At that point, they need split, and you can do it at this time of year. 
    It's quite easy, but a photo will help, as said   :)

    I'm assuming it's bearded irises you have  :)
    It's a place where beautiful isn't enough of a word....



    I live in west central Scotland - not where that photo is...
  • janinerjaniner Posts: 66

  • janinerjaniner Posts: 66
    The above is a pic of my raised bed with bearded irises. They were beautiful this year. I'm just a little worried of it getting overcrowded in there.
  • Pete.8Pete.8 Posts: 11,340
    I have several clumps of bearded iris.
    About every 3-4 years I dig the lot up and divide them, throwing away the shrivelled old rhizomes.
    You want a nice fat rhizome with roots and leaves to replant.
    Cut back the leaves to about 6" - this prevents wind-rock over winter which would damage the fine new roots that are forming.
    When replanting I make 2 grooves in the soil for the roots with a small ridge in the middle for the rhizome to sit on.
    The rhizome sits on top of the ridge so it is almost completely exposed to the sun (so facing South ideally - mine face south west) and the roots go into the grooves either side and are covered with soil.
    When replanting, the rhizome needs to get as much sun as possible on it, so ensure the rhizome is in the sun and not being shaded by the leaves.

    Ideally this process is done about 6 weeks after flowering, so July, but if you do it soon they'll be fine.

    Last time I done mine, after replanting I still had about 50-60 fresh new rhizomes.
    I advertised them on Freecycle and they were all taken the same day.

    This may help too-
    https://www.rhs.org.uk/plants/iris/dividing

    Billericay - Essex

    Knowledge is knowing that a tomato is a fruit.
    Wisdom is not putting it in a fruit salad.
  • FairygirlFairygirl Posts: 55,117
    Excellent advice from @Pete.8.
    I'd say those look very congested and could do with splitting. There's very little room by the look of it. 
    The only problem is finding room for them all once you've split them!
    I used to find I'd need to give them a bit of basic support after re planting as it's always windy here, but it depends on the site as to whether it's needed. 
    It's a place where beautiful isn't enough of a word....



    I live in west central Scotland - not where that photo is...
  • janinerjaniner Posts: 66
    Thank you everyone. Yes, I think I may need to split them and give half away. 
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