Monday 11 July 2022

Bearded Iris - summer tidy-up

It's that time of year...  


... and the Bearded Iris are finally over.

They've been beautiful - these are my own ones, at home, left -  but now they are done, and it's time to tidy them up for the summer.

The first job is to dead-head the flowering stems as the blooms fade, in order to prevent them going to seed, which wastes energy which we would much rather they put into next year's flowers.

Personally, I go round my Iris plants every couple of days, with a pair of scissors, and I snip off the fading flowers individually: most of my Iris (plural of Iris, someone: Irises? Ireeez? Who knows...) are lush bearded ones like these, so the fading petals tend to wrap themselves affectionately around the not-yet-opened buds, and if they get wet, urgh, they turn into that organic papier mache (as the roses do in wet weather) which then prevents the newer flowers from opening.

Then, once every bud has opened, flowered, and finished, it's time to deadhead the entire flowering stem: I am constantly surprised at the number of people who just nip off the top few inches, leaving a bare, truncated stem sticking up above the leaves. I don't think that's pretty...

Here's a good example, left: a mad jungle of beheaded flowering stems, overcrowded leaves, and assorted weeds.

Not only does this look messy, but it's a haven for bugs, slugs and snails.

So it's time for the summer tidy-up!

Firstly, the flowering stems. Gird up your loins (I have never known exactly what that means: I mean, I know what "loins" are (nothing to do with lions, or lino) and the phrase "girding up" seems to imply lifting something, with overtones of "girdle". So I have a sort of vague impression of heaving up the clothing which is otherwise flapping about the ankles, then tightening up a belt of some kind. In my mind, this is preparatory to doing some active, which requires freedom of movement. If you have a better idea, do please feel free to tell me via comment, below.) 

(Hmmm, I have just gone and looked it up for myself. I was not far wrong! Take the long flappy robe which you are wearing (!) pull it up to backside height, take all the spare fabric from front to back, between the legs, then reach behind with both hands, grab the "corners" as it were, bring them round to the front and knot the fabric. Thus creating a cross between shorts and a nappy - very practical, for leaping about energetically.)

Where was I? Oh yes, gird up your loins, grab the secateurs, wade in, and take a close look:

Here is a clump of Bearded Iris/Irises, and I have added arrows to point out the flowering stem, as it's not so easy to see, from this angle.

Once you have done a few of these, you will notice that each rhizome - that's the beige-coloured long thick lumpy thing, growing just above ground level - has just one flowering stem, at one end. This makes it easier to track down the flowering stems: they are thick round things, sprouting from the very end of a rhizome.

I have, incidentally, already cleared the weeds. and have trimmed the clumps in front, in order to show you what I am doing.

So, there is the strong, solid, round, flowering stem - as opposed to the bendable, flat, leaves.

Track it down to the very bottom, the lower red arrow, and cut it off cleanly at that point.

Can you see how there are big fans of leaves, one to either side of the (now removed) flowering stem?

Those are where next year's flowering stems will originate.

Iris (Irises? Still not sure) have an interesting way of growing: they start with a single rhizome, that fat light brown thing, at soil level.  This produces a single flowering stem at the end, but they also produce a new, smaller, bud to either side. This develops into a fan of leaves and a new rhizome, over the summer: then next year, those two rhizomes will each send up a single flowering stem, while the original one will never flower again..

So from one individual rhizome, you get one flowering stem this year, two next year, four the year after, and so on. After a few years, there are lots of rhizomes and lots of flowers: but then the clumps get so congested that they stop producing new flowering stems, and at that point they have to be lifted and separated. Ah, that Playtex moment! (showing my age now...)   That's a subject for another post, so for now let's get back to this one.

Take each finished flowering stem in turn, then, and cut it off right at the very base.

I know that, technically, the flowering stems are green and can therefore photosynthesise: I know that they often have smallish leaves on them... but once the flowering is done, I much prefer to cut them right down to the very bottom. 

Next step: trim back the leaves.

Now, this might not be to your taste: some internet sources will say not to cut back the leaves, but I was taught to do so, twenty years ago, by a lady who had large numbers of Iris (Irises?) ..hmm, shall we say who had a large Iris collection (*grins*), and who had been growing them for many years. She told me (and I checked, I looked it up for myself, and she was correct) that the rhizomes of Bearded Iris require a certain amount of sunlight in the current year, in order to flower the following year. She used the term "baking" - they needed to "bake" in the sun, she used to say.

So when it was time to remove the finished flowering stems, she taught me to cut the leaves down to a neat fan shape, in order to reduce the shade they cast on the rhizomes. I have done this ever since, and every collection of Iris plants in my care has flowered beautifully, so I will continue to do it!

This is the effect we are aiming for, then: flowering stems removed, leaves cut back to neat fans to let the light in, all weeds removed.

Sharp-eyed readers might also notice that I have pulled off all the brown, dying leaves as well. There is no point leaving dead leaves on the plants: it just encourages slugs and snails, and it also traps moisture at ground level, which is very bad for Iris rhizomes, as they are prone to rotting.  So all dead leaves are gently pulled off: if they don't want to pull off,  then snip them off as low as you can, and next time you are weeding the area, the stumps  will have died back sufficiently to be pulled off.

And that's pretty much it: all material can be put onto the compost, I usually chop the flowering stems into smaller sections to help them rot, but that's probably not necessary.

Within a couple of weeks, the new leaves are growing out from the centres of the fans, so they look a bit weird for a short time: but the end of flowering season coincides with the middle of summer, ie when the sun is highest in the sky, so it's the best time for the "baking of the rhizomes" to take place. 

I leave the new leaves to regrow, and they continue the good work of photosynthesising for the rest of the summer. 

As for feeding, the one thing you should not do with Bearded Iris is to mulch them: the rhizomes need to be sitting on the surface of the soil, in order to bake, and in order not to rot! They are very prone to rotting, which is why they like a well-drained soil.  It's ok to give them a bit of balanced feed now and again: mine get a sloosh of diluted liquid seaweed feed, usually once the leaf fans have re-grown, on the basis that I'm helping them to store up energy for next year's flowers. 

Again, though, the lady with the extensive Iris collection didn't feed hers at all, so I don't feel the need to pamper mine too much, and they certainly seem to thrive on a fair amount of neglect!

So there you have it, a quick ten minute tidy-up of the Iris bed, allows the sun and the light into the rhizomes, reduces slug and snail damage, helps to promote flowering for next year - and looks neater!



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