Gardening expert Mary Lovell-Smith shares her favourite species of iris

In Greek mythology, Iris was the goddess of rainbows and like its romantic namesake, these tall, elegant blooms come in a multitude of colours

I would like to say that all irises are beautiful, but they are not. Given the genus contains up to 300 species, that is hardly surprising.

Despite often being called the queen of the flowers, some irises are the epitome of streamliner elegance. Others are over-the-top gorgeous, some merely pretty, while others unequivocally plain.

In my Christchurch garden, the first – or last – iris to flower is Iris stylosa (aka Iris unguicularis or Algerian iris). Usually, it starts to bloom in May and continues through into August – I think. For its slender blooms of this gentle and shy iris are often hidden in the leaves and have to be sought out. A native of Greece, Turkey, western Syria, Algeria and Tunisia it does better in conditions emulating the lightly shaded, rocky poor soil of its natural habitat. Too rich or kind a setting and it produces too many of its grass-like leaves and not enough flowers, which most commonly come in shades of mauve, with white forms sometimes available. In late summer, some of these leaves can be cut back to expose the nascent flowers to more light. This will also discourage slugs and snails, which love the fragile blooms. Although short-lived (and shortstemmed), the sweetly fragrant blooms can be picked, or rather plucked gently, just as the bud is showing colour, brought inside and placed in a vase where its unfurling can be observed. Don’t bother with a bunch for a single bloom will bring just as much joy in the bleakest of winter days.

Next to bloom is the pretty, jolly almost, Iris japonica, which sends up sprays of fresh, open pale lavender flowers from late winter. As the flowers open in succession this winsome display can last for several months. A crested iris from Japan and China, it flowers best – as, of course, all plants tend to – in conditions resembling its wild habitat. In this case this is open damp woodlands, or by streams. With its shallow roots put out periodically by the creeping aerial rhizomes it cannot tolerate drought. Some find the profusion of leaves burdensome, especially toward the end of the season when they get tatty, but that’s all part of plant’s lifecycle and needs be accepted with good grace.

Then, all of a sudden, I have a rush of irises blooming. First, by a hair’s breadth, are those iris bulbs sold at any and every garden centre in autumn – Dutch irises, which are named for the breeders’ rather than the bulbs’ country of origin. The bulbs are really hybrids of Xiphium species from Spain and the erratic but beautiful Algerian Iris tingitana. To perform at their best, give these elegantly simple irises plenty of sun and free-draining soil. Lime may be added, but not too much compost or manure, else you may be encouraging viral or fungal diseases. Despite their appearance in catalogues and garden centres in autumn, bulbs are best lifted once their foliage has died down and replanted in late summer.

Hot on their tails are my various bearded irises, of which I have many cultivars in a rainbow of colours and fabulous forms, and no names. I once called these flag irises in an article – a term referring to their striking blooms fluttering above other plants like flags in a breeze – only to be reprimanded by the local horticultural society for the imprecision of using a colloquial name. There is no room here to tease out all the differing sorts of bearded irises, suffice it to say these are the ones with rhizomes, which produce fans of sword-shaped leaves and a strong, single stem bearing one or two flowers. These like sun, especially baking down on the rhizomes in summer, well-drained soil, a little lime in winter and a general fertiliser in spring and autumn.

As my flag irises are sailing full steam ahead like bustling Victorian matrons, my Iris orientalis (aka Iris ochroleuca) are quietly, serenely and without any fuss preparing to stun. Although I confess to having other irises dotted carelessly throughout my garden, these elegant tall white ones (with their gold signal patch to help pollinators find their way in) grow by themselves in two large and ever-increasing stands. Their relatively sparse leaves are erect and given enough water, the slender flower stems can reach nearly well over 1.5 metres high. In their native north-east Greece and west Turkey, they grow in damp meadows, marshes and ditches, but they seem to like it well enough under the kanuka in my rocky, seldom watered hillside garden.

My garden is too dry and my water-saving ethos is too strict to grow the lovely, lush Louisiana irises. I can only admire their generally large blooms in other people’s gardens. Five species make up this group, and with hybridising and breeding, it is hard to identify which is which. Best to check out the photographs to ensure you get just what one wants.

Elsewhere around the town, Siberian iris blooms in shades of white, yellow and purple, are pushing up through an abundance of fine leaves. The delicate, finely veined flowers are worth the messy leaves, as is the willingness of the plant to grow in conditions far from the wet meadows, swamps and lake margins of its native habitat, which spreads from Switzerland to Lake Baikal in Siberia. Ask around if you want some as it is gratifyingly common throughout the country. Transplant when dormant, from May to September.

Many will turn their nose up at my final iris. Some are disdainful of its inconspicuous, dirty lemon, veined flowers; others of its readiness to self-seed from its way more conspicuous fiery orange berries; and still more of the distinctive odour the leaves of Iris foetidissima aka stinking iris emit when bruised (though as garden writer and gardener Vita Sackville-West of Sissinghurst, England, archly noted: “There is no need to bruise leaves, a wanton pastime…”). Like Iris japonica, this native of the British Isles is evergreen. But what’s more in a most useful way, it tolerates those shady reaches of a garden where little else deigns to grow.

Words by: Mary Lovell-Smith.

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