Notes on Iris
A deep violet blue form of the Algerian Iris, I. unguicularis (syn. I. stylosa), has flowered in the dry garden all winter. Iris 'Mary Barnard' flourishes in a very difficult, very dry spot at the base of an olive tree where it also competes with a nearby privet hedge.
The plant that can be called “typical” Iris unguicularis is found in Tunisia as well as Algeria. This variety which is most often found in Australian gardens has large, primrose fragrant, soft lilac flowers nestling under long arching leathery leaves. There were two clumps of this in the garden when Criss and I first came here 16 years ago. Each was so large they must have been growing in the same spot for at least 50 years.
Brian Matthews, in his monograph on the genus, suggests that the lilac pink flowered, short leaved Iris ‘Starkers Pink’ can be referred to the Cretan population, Iris unguicularis ssp. cretensis. Matthews finds this particular clone difficult to grow in England but it’s easy enough to satisfy here. Rabbits occasionally graze it and they will do serious damage if no action is taken. A light dusting of blood and bone around the bed is enough to deter rabbits for a few weeks by which time, with any luck, they should have forgotten all about the Iris.
Last summer I planted a hundred Iris reticulata ‘Harmony’ in a hot sunny spot in the dry garden under a carpet of a prostrate thyme, Thymus longicaulis ssp chaubadii. These little bulbous Iris are native to Turkey, Iran, the Caucasus and Central Asia which are all places where the summers are long, hot and dry and winters are cold and bleak which describes our climate here at Ascot pretty well.
Iris reticulata does best in alkaline or near alkaline soil. Our soil is naturally very acid. The paddock we carved the dry garden from had a PH of 4.5 before we added the equivalent of two tons of lime to the acre to it. We applied the lime before we planted anything at all and every year we still dust the garden with lime during winter to keep the soil sweet. Whenever I replant an area the soil is dug as deeply as possible and as much humus as can be spared humus is mixed in, This year I used spent mushroom compost. Humus not only keeps the soil open it also helps to keep soil moisture levels up.
Over the last few weeks all one hundred bulbs of Iris ‘Harmony’ have flowered. Each 10 to 12 centimetre tall stem carries a rich blue, yellow crested, heart stoppingly, exquisitely beautiful flower. They're brave too as the frost, hail, snow, sleet and rain during their blooming period did no damage. I am so besotted by them that I walk down to the dry garden to look at them, doe eyed, a dozen times a day no matter what the weather.
Botanists don't include the Mourning Widow or Snakes Head Iris in the Iris genus at all. Hermodactylis tuberosa has a unilocular ovary, that is it has an ovary with a single chamber, whereas true Iris have a trilocular ovary. In all other respects Hermodactylis is an Iris. I first saw this bulb 45 years ago flowering in a garden belonging to an International Brigader, Arthur Howells. His garden in the Dandenongs had a patch of Hermodactylis, some two metres by five metres, naturalized under a Mt. Fuji cherry. It does well growing in full sun or shade. Our group in the dry garden flourishes under an olive tree. The sombrely beautiful black, yellow and green flowers are held on 35cm stems during August.
A seriously good book, one of the best gardening/plant hunting books I’ve ever read is Janis Ruksans - Buried Treasure. Recently published it details a Latvian nurseryman gardener’s journeys into Central Asia looking for rare and beautiful bulbs. Tulips, Alliums, Iris, Crocus and Fritillaria are just some of the genera he writes about with passion and good gardening sense. It is one of my four best gardening books. It's worth tracking down a copy.