July delight with winter irises

Press, 25 July 1986, Page 12

July delight with winter irises

Gardener’s I. DIARY

Derrick Rooney

One of the prettiest things in many Canterbury gardens right now is the “winter iris,” Iris unguicularis, which grows wild in North Africa and the countries bordering the eastern Mediterranean.

The common garden forms are of Algerian origin and have vigorous leaves, fairly broad for the species, and flowers ranging in colour from deep violet blue to pale lavender. The most common form in Canterbury gardens has light lavender-mauve flowers which are very sweetly scented. A characteristic of the species is a white patch, striped centrally with yellow, at the base of the falls. Seedlings vary in the size and shape of the white patch and in the amount of lavender veining on it. In all the Algerian forms the leaves overtop the flowers, and some gardeners cut away the foliage in autumn to make the flowers more visible. I don’t; the flowers look far more natural nestled among long foliage than on a bed of nail-like stumps. Fortunately, no such problem arises with the eastern forms from Greece which have been offered by a few nurseries in recent years. These have smaller, narrower leaves than the African form, and the flowers are carried well clear.

“Starker’s Pink,” which has some pink in it but is

really lilac mauve, is one of the best of the Greek forms. The colour is better than it sounds, and it comes true from seed if the parent is grown in isolation from other unguicularis forms. This Is fortunate because the original clone, which is still available, is rather a weak grower and susceptible to virus. I’m not sure whether I still have it.

When I remade part of the garden several years ago “Starker’s Pink” had to be moved from its original site, and in its new home it grew poorly. So .1 moved it again, but I can’t remember where I put it; there’s a plant in the rock garden that just might be “Starker’s Pink,” but I’ll have to wait until it flowers again to find out.

Even smaller than the Greek forms is Iris “cretensis,” a variant with very narrow, short leaves, slow growth, and deep violet flowers shading to red at the base of the standards.

There isn’t much white on the falls, and the yellow is in the form of a signal patch rather than a stripe. Despite the small foliage the flowers are normal size, making this the most choice plant in the whole unguicularis complex.

It yields up its pleasures reluctantly, however, being resentful of division and transplanting. Transplants may take several years to re-establish and flower freely.

Several named varieties of the Algerian forms have been available in the last few years. A newcomer to my garden is “A. K. Aslett,” named for a noted British plantsman; I don’t know much about this, and it hasn’t flowered yet.

"Walter Butt” and “Mary Barnard,” also both named for British gardeners, were found in the wild in Algeria. Both have sweet-scented, clear lavender flowers, the latter a shade or two darker than the former. ... A vigorous deep lavender form which flowers in the spring only is sometimes seen in gardens; a

big clump of this in my garden was infested with couch grass and had to be sprayed and removed, but many seedlings; have since appeared. This is called "Speciosa.” Also spring-flowering is Iris iazica, a subspecies in the group from Turkey, where it grows at the fringes of woodlands around the Black Sea, and likes shade and damp soil — in contrast to the sunloving Algerian and Greek forms.

A white form of Iris unguicularis was first found by a Mr Edward Arkwright near Algiers about 1870, and now several white forms are in cultivation. These vary in quality, and unfortunately the most common has squinny little flowers and poor weather resistance. There are some better ones, such as “Bowles White,” and there" used to ' be a very good New Zea-land-raised white called "Winter Snowflake,” but I don’t know where it might be obtained now. Does anyone grow it? Seedlings of both the white and lavender forms can vary quite a lot in the size, shape, colour, and markings of the petals, and in the length and ' time of flowering. It’s worth raising a batch of seedlings from time to time just to see what you can get. They take about three years to reach flowering size.

If seed seems a bit hard to come by, don’t despair* The seed pods of this iris are at ground level, well buried among the leaves, and you have to search very thoroughly for them.

The pods can last for several years, hidden in the plant; the seed does not deteriorate while it remains attached to the plant, and usually germinates very quickly if collected and sown immediately. But it loses viability if harvested and stored dry for a few months. There seems to be little logic in this.

What seems to be a long stalk on the flower is actually just an elongated floral tube, and the actual reproductive organ — the ovary — is right down at ground level. With a bit of practice you can learn to give the flower a sharp tug so that it snaps off just above, the ovary, leaving a good -! length Jof. “stem?, io p)it in - a vase. They: last for; s'ev-s eral days when picked, but bruise very easily, which is why you don’t see them on sale as cut flowers. '