Tuesday, 2 July 2013

Iris rhizome splitting and replanting

There's plenty of Iris in my garden - they like the limey soil and the hot Mayenne sun and so they flower profusely and spread rapidly.  They make a magnificent display when they're going strong, but after about three years or so they get overcrowded and become less vigorous.  At this point they need to be dug up, separated and replanted in fresh soil.

The time to do this is, according to the books, 6-8 weeks after they have finished flowering, so they can build up their reserves during the rest of the year for next Spring's display.  I am perhaps a bit early, but on the other hand, Spring was cold and late here, so I'm going for it.

Each original plant will have produced 10 or more offspring, and there's a limit to how many I can keep in my garden, so the result of this excercise is a large number of Iris plants that need good homes.  Unfortunately I regard them in a similar way to the kittens produced by a domestic cat - I have to find them a good home.  So there's some for Leo, some for the lady gardener who works at the music school, some for Marie down the road.  Those I can't get rid of end up in a box in the car park up the road with a notice "Free to good home".  They all seem to go in the end.

Here's what you do. The hard part is preparing the new bed, that should get at least 6 hours of sun per day, when it's not raining that is.  Here in my garden it involves pick-axeing the stones out of the ground, getting the perrennial weed roots out and adding a slow fertiliser to the soil.   When the bed is ready, dig up the clump that needs splitting, and separate the rhizomes into individual plants.  You can trim back the leaves to help with their stabilty once planted.   Then plant in your sunny location and water them when it gets too dry.   Give the spare ones away.




6 comments:

  1. We spent the last couple of years learning about flag irises, quite a lot from you. Last year we gave up the unequal struggle of preventing their taking over our tiny beds and bought an earthenware wide bowl to keep them in. Not enough sun here yet to see any results, but they seem healthy.

    I'm guessing we need to lift them at least every couple of years and replenish with manure before replanting. passing plants n to friends when we have spares.

    She Who Must Be Obeyed is heavily involved with Dartmouth in Bloom and is preparing for judging. She's entered our entire row of cottages as a neighbourhood, but other people's illness, absence and death means she has just weeded and tidied eight out of our row of 10 front gardens. for judging on Friday.

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  2. Hi Tim, good luck with the blooming competition! You should add garden lime as well as manure to the soil, because manure is usually slightly acid. Keep lime off the hands and don't breathe the dust since it burns!
    Hope you're both keeping well.
    M

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  3. Garden lime it is. All Devon soil seems to be acidic, as witnessed by the number of disused lime kilns in the area. Not a local industry one wants to be anywhere near when in operation. Many years ago a local lad was incinerated in one here when he fell asleep by the top and rolled in. I suspect CO poisoning first, or hope so. Less unpleasant for the boy.

    I lend labour to Dartmouth in Bloom, but am wisely not a committee member. I tend not to be great on committees. I call a spade a shovel just before burying someone with it, usually.

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  4. In the words of the great collaborator

    'Ah yes, I remember it well'....

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  5. Looks like hard, dedicated work... you need your own TV show on the Beeb!

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  6. Different world. Rewarding world.

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