Iris sibirica - autumn tidy up

 Does September count as autumn?  Yes, I think it does: of course, the actual weather makes a difference, and we've had quite a mixed batch of weather lately, to the point where sometimes it's hard to know how many layers of clothing to put on in the mornings: for the last week or so I've been going out in shorts, fleece and sleeveless jacket, wondering if I ought to go to "longs" - but by mid morning I have been sweating, and glad to peel off a couple of layers!

Some years, the Siberian Iris look spectacular well into winter, but this year, they are already starting to look very tatty.

"What do we do with them?" one of my Patrons pleaded:  "They look terrible!"

Firstly, let's look at what we are talking about. Iris sibirica is the fellow, and Siberian Iris, or Flag Iris, are two of the common names. And this is another moment to make that point about using "proper" names, because Flag Iris is usually taken to mean those very large yellow iris which you find growing in the water, along rivers, and sometimes in ponds: proper name Iris pseudocorus. It's a gorgeous thing, but, being a water-dwelling species,  it would not do well in your well-drained garden bed. ("Unless it was an island bed, ha ha") (sorry...)

Back to  Iris sibirica... They produce tall, stiff, slender stems bearing several flowers per stem, which appear in May and June, and they have very narrow, long, foliage. Which can get a bit floppy.

They are usually blue: and because they flower so early, we usually dead-head them, otherwise they spoil the look of the bed, quite apart from them spending a lot of energy making seed, which is quite unnecessary because they spread quite rapidly into good sturdy clumps.

However, in some years, the stems stay very straight, and the seed pods turn a smooth black, and they actually look quite attractive... typically, I can't find a photo to show that! In which case, you can put off cutting them back until such time as they no longer look attractive.

So there are two phases of maintenance for this plant: as soon as they have finished flowering, cut back each flowered stem right down to the ground (unless they are very straight and tidy). Leave the leaves (? always looks odd, writing that!) because they need to feed up the rhizomes for next year.

But by late summer/early autumn, those leaves are pretty much done, and are turning brown. Not so pretty! So now it is time to cut them back.

Here's a fairly typical example, left: not very appetising, is it?

The leaves are lank and flopped over, and you can see by the colour - pale green turning to brown - that they are no longer actively photosynthesising.

This year, the flowering stems have not turned a nice, glossy dark brown or black - instead they are  merely brown, which is a bit disappointing: but at least they are still standing  up straight.

My first pass, for plants like these, is to rake out the dead material by running my gloved hand through the clump. 

Often, that can freshen up the appearance quite considerably.

Next job is to cut back the foliage to just a few inches, for tidiness: as I said, it's not photosynthesising any more,  but I never like to cut this material right down to the ground, partly because then I might forget that the plant is there, and accidentally trample all over them while weeding.

Here we are - right: all the dead material has been raked out, and all of the foliage has been cut right back, to just a couple of inches, leaving the stiffly upright stems.

This allows me to do a further raking, to ensure all dead material is out:  then I can see if there are weeds infiltrating the clump and, if so, remove them.

I can also then assess the clump, to see if it is getting over-crowded, and in need of division: in this case, not so much, because as you can see, it's a healthy, vigorous clump. 

The flowering stems can be allowed to stand as a display until either they flop over, or until we get tired of looking at them.

So there you have it, easy peasy ways to tidy up your herbaceous perennial beds, in the middle of summer!

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