Cornucopia
32: Autumn 2013
Iris Unguicularis
Trisha Cooper
Previously known as Iris stylosa, its common name is the Algerian Iris. What a joy this is! A most beautiful plant flowering between November and March.
Just when we need cheering up, this little treasure surprises us every year, its size and delicacy more typical of a summer’s day. The tiny bud spears appear followed by the sweetly scented, delicately-marked, lavender-blue flowers produced in abundance.
A vigorous, rhizomatous bearded perennial needing a position at the foot of a dry wall, it thrives on neglect! The blooms are 2″ -3″ across (5 cms – 7.5 cms) on very short stems nestling in the evergreen, scruffy, tough grass-like foliage 12″ to 20″ (30 cms – 50 cms) long, depending on the variety, in congested clumps. Not noticed until the buds form, sometimes November or Christmas then on and off until Easter. Erratic flower production cleverly avoids weather damage – buds are frost-proof but flowers are not. I like to pick a bud and watch it unfurl indoors enjoying the perfume. So very cheering!!
Although found in Algeria, it grows in North Africa, Greece and its islands and the natural habitat is a lightly-shaded rocky habit.
To grow in the UK it needs full sun and a well-drained, dry, poor to moderately fertile soil that is neutral to acid. It is fully hardy to -15°C (5°F).
Some advocate cutting the leaves back in January with shears to expose the flowers and let the sun ripen the rhizome; others remove all the dead leaves in the autumn and some place slug killer in the centre of the clump to prevent buds being eaten by birds. I do nothing. They are at the base of a ragstone chimney breast facing west and they are fine. Flowering nearby in the autumn are South African bulbs, pink-flowered Nerine bowdenii and perennial Liriope muscari, even though the latter is said to prefer a little shade and that unknown soil (moist but well-drained).
Some plant cistus, lavender or santolina nearby – these can be sprawling shrubs that would need keeping in check.
Varieties:
Iris unguicularis ‘Mary Barnard’ is tidier than most as the leaves are shorter. The flowers are a sumptuous purple.
I. u. ‘Walter Butt’ has flowers that are pale lavender blue, free-flowering and heavily scented.
I have the above but others available include I. u. ‘Abington Purple’ and I. u. ‘Alba’.
First published in the Essex Group Newsletter May 2012 and subsequently in Cornucopia Issue 32.
© Copyright for this article: Trisha Cooper
This article was taken from a copy of Cornucopia that was published in 2013. You could be reading these articles as they are published to a national audience, by subscribing to Cornucopia.