Dividing and maintaining bearded iris

I love irises, the range of colour is now amazing and yes their flowering time is short but they foliage is just as important for me within the garden.

There are a few groups of irises out there and working out if yours are the bearded type is pretty easy. If they have large fleshy rhizomes that love to be on the surface of the soil, then chances are it’s a bearded iris. If you are looking for exact names then iris pallida, germanica are just a couple to look for

This is Iris Cannington sky and you can see the beard circled above, this is where they get their name from

The bearded iris love to be in a sunny but moist with good drainage spot within the garden, ideally so the large rhizomes are exposed and being baked by the sun. They don’t like being covered in mulch!

Lifting and dividing is best carried out soon after they have flowered, so from end of June into July. This is to give them maximum time to settle down again and start producing the flower buds. Dividing is needed to stop the clumps from getting too crowded and so effecting the growth and flowering of the clump. It’s not something that needs to be done every year, once every few years is ideal and it’s best to divide when the plant needs it.

Tools and equipment needed

  • Hand fork/border fork
  • Secateurs/knife
  • Trowel

Level of difficulty

Pretty easy to do

A group of bearded iris that are crowded and need dividing you can see the new fans of foliage are on top of each other
Just ease the clump up with a fork, just taking care to not damage too much. Quite often the plant lifts within its own small clump
1 is the older rhizome that’s not really doing much, that’s what you need to remove. 2 are the newer rhizomes that you need to keep
Showing you with my finger where to need to remove the new section from the older plant
You can either break it off that this joint with your hands or use secateurs to make a clearer cut
I like to keep it to 2 fan sections per plant as I feel it’s a good number for the section to recover quickly
After I have my new plant I cut it back, this is called fanning the irises. This helps to both reduce the stress of the plant and also tidy up the older leaves. The older brown leaves are just pulled off the.
The hieght I reduce them to Depends on the vigour of the plant, this one is vigorous so it’s the base of the secateurs to the tip
Then cut the top off the foliage either in a Straight line or in a nice curve, I prefer curves myself
All cut
Pulling the older leaves off at the base. I would repeat this part of fanning the irises each year
Then replant so the rhizome is just on the surface and the roots are in the soil.
And then sit back admire your work and look forward to the extra flowers and foliage display next year

4 Comments Add yours

  1. tonytomeo says:

    Are there many cultivars of Iris pallida?! I think of the popular bearded iris as the countless hybrids of Iris X germinica, with Iris pallida as a separate group of only about four cultivars. Common Iris pallida with lavender blue bloom happens to be my all time favorite iris. The only variations that I am aware of bloom white or darker purple, or are variegated.

  2. David S. says:

    Hi Tony and Tom
    I, too, love Iris pallida..It was a personal favourite of the late Graham Stuart Thomas who valued it as much for the colour and structural benefit of its foliage as for its perfect flowers. An all time favourite indeed!
    On varieties, I am not aware of any further forms to those mentioned

  3. First year I’ve had any Irises to divide. Between 3-5 years ago we began planting in earnest, and picked up several Iris varieties as single rhizomes. Those lot are still plucking away, but one group of Iris ‘Nibelungen’ looked to need dividing.

    Using your advice and technique I ended up with 22 separate rhizomes. Some were single fans, others were triples, in about an even 50/50 split.
    I was rather surprised to have so many ‘new’ plants and then had to figure out where I was going to re-establish the divisions!

    I made sure to brush away the mulch that had gathered on several of those previously mentioned and that haven’t flowered yet. Possibly next year there will be a burst of new blooms for the effort this week.

    Thanks Thomas for the great tips!

    1. thomashort says:

      Thank you and so pleased you managed so many plants 😀

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