How to get the best display from Iris unguicularis

Colour-wise, there's often not a lot going on in winter, but the Winter-flowering Iris, or Algerian Iris, is something to lift the spirits in areas of the garden which might not otherwise produce much in the way of gardening joy.

Iris unguicularis is their proper name - pronounced Un-gwick-you-la-riss, in case you've never tried to say it out loud - and they are always found to be flourishing in the driest, dustiest, poorest soil imaginable. Their typical, and favourite, location is the base of a south-facing wall, with the worst soil to be found, and preferably with an under-layer of builders' rubble. An area that never gets any compost or manure, and very little water, is just about perfect for these tough little plants.

Why? Well, they come from the Mediterranean regions, and they like it hard. Unfortunately, they also like it hot, in the summer when they are dormant, so after a poor summer, we can't expect too much from them: but normally, they will please us with a succession of lilac-blue flowers all through the winter.

They manage this by cunningly producing buds which are resistant to frost, so even if the weather turns bad, the unopened flowers will survive perfectly well until the next milder snap, at which point they will burst into sudden life.

The down-side of these otherwise valuable winter flowers is the foliage: by the time they flower, they foliage is longer than the flowering stems, so you can barely see them: and the foliage itself is looking really tatty, with dead old leaves in amongst the drooping, barely-alive ones, and all looking really rather sad and unpromising.

The trick is to get out there now, in early/mid October, and chop them down ruthlessly. 

And when I say ruthlessly, I mean like this:

Here - left - I've chopped down the front of each clump, leaving the back as a demonstration to show you how big they were before I started.

Don't leave them like this: cut down all the foliage, ruthlessly.

(Aside: I often wish I'd been christened Ruth, rather than Rachel, because then I could be Ruth The Ruthless Gardener....)

Here's another clump, in the same garden, with one annoying flower , which I tried to cut carefully around.

(When I say "annoying", it was a "lovely!" flower, it was just a bit annoying to have to cut round it!)

Most people can't bear to be this harsh with their plants -  you know how it is: no-one likes to hack back foliage that it still quite green, and invariably this job gets put off and put off, until the new leaves are showing above the old ones, and it's too late to cut them back.

However, if you get out and check now, there is still time!  

Being truly ruthless leaves you with a brutal skinhead of foliage, more brown than green. Rake through the clumps with gloved hands (I use my faithful Daisy Grubber) and pull out all the dead leaves, debris, any weeds etc, leaving nowhere for the slugs to hide.

Once this is done, the clumps will be more green than brown, and ready for the winter. In no time, the sharply pointed buds will be appearing, and passers-by will once more say “Coo! What lovely flowers!”.

The work above was done on the 5th October last year, and here - left - is the same area (note the black downpipe) on the 23rd November.

As you can see, most plants have died back for the winter - just look at that bare Hibiscus! - leaving mostly the roses and the evergreen Hebes.

But our Iris unguicularis is now flowering, and we can see the flowers, because they have not yet been overtopped by the re-growing foliage.

I say "not yet".... 

... and here we are - right - on the first of March this year.

As you can see, the leaves are now overtopping the flowers!

But at least we were able to see the flowers all through the winter, and they are still providing a little bit of colour, swamped though they are.

One last point, don't worry if your clumps start to look really congested: Iris unguicularis are one of those funny plants, like Agapanthus and Nerine bowdenii, who actually flower better when they are crammed together!
 

 

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