What’s not to love about irises? Especially as they come in almost every colour under the sun and survive extreme heat, wind, and dry soil, says Adrienne Wild
Irises have been a favourite flower since the Chinese fell in love with them thousands of years ago.
Their picture-perfect blooms have also been a source of inspiration for many artists, including Vincent van Gogh and the French impressionist painter Claude Monet, who was so in love with irises that he also dedicated an area of his garden at Giverny to them.
In British gardens you’ll typically find the ever-popular bearded types planted in traditional cottage-style borders alongside globe-shaped blooms, such as alliums and peonies, or bold daisy flowers planted en masse in blocks of single colours.
More recently, though, garden designers are using them in contemporary prairie-style planting schemes where they are randomly planted in among ornamental grasses, as well as in patio containers.
Spoilt for choice
Also known as flag iris, the flamboyant flowers, which can be anything from 7.5cm to 15cm across, are produced on stiff stalks above fan-shaped clumps of grey-green sword-like leaves.
They are made up of three upright petals, or ‘standards’, above lower petals, or ‘falls’, that sport a caterpillar-like beard of soft hairs along the outer petals.
There are hundreds of varieties to choose from and I think thompson-morgan.com offers one of the best selections. You’ll find varieties with frilly petals, which are bicoloured, freckled, ruffled or lace-edged.
Bearded irises are always categorised into six groups according to their height, which start at 10cm and go up to 1m tall. As a general rule, the shorter the bearded iris, the earlier it blooms.
With careful selection it’s therefore possible to have flowers from April to mid-June, or one or two weeks later if you live in the Midlands or further north. Many irises will re-bloom later in the year, too, and if weather conditions permit, will produce even a third or fourth flush of flowers.
Almost every year there are new and exciting varieties available, making them highly collectable and a must-have for the garden. Many varieties are also sweetly scented, which is a useful quality if you are growing them for cutting.
Often the most gorgeous and reliable varieties have won awards, such as the tall, fragrant Iris ‘Clarence’.
This popular iris has ruffled blooms in white, blue and violet with a creamy beard. It flowers in late spring or early summer and re-blooms late summer or early autumn.
Dark and moody
Another outstanding tall bearded variety is ‘Superstition’, which has ruffled and wavy edges, shiny black flowers with undertones of purple. Plant it against a backcloth of the silver foliage of yarrow, Achillea ‘Moonshine’.
With so many colours to choose from picking your favourites can be difficult, so begin by finding colours that compliment your existing border schemes. For example, if you want luscious, deep purple flowers to contrast with yellow or pink-flowering perennials, then look no further than the RHS Award of Garden Merit winner, ‘Titan’s Glory’.
This spectacular iris flowers during early summer, producing three to four branches with up to eight buds, which open over a long period to reveal ruffled blooms up to 10-20cm across.
The deep wine purple blooms of ‘Diabolique’ also make quite an impact. It looks stunning when set among the slightly shorter ‘Lemon Mist’, which has heavily scented, large ruffled pale lemon flowers with white ‘falls’ edged by lemon.
Another worthy iris is ‘Jesse’s Song’, which puts on two fabulous shows in spring and early autumn.
It has copiously ruffled blooms with white petals elegantly marked with violet. For sophisticated style, partner it with Iris ‘Rajah’, which has blooms with bright yellow standards supported by brown falls marbled in white veins close to the beard.
Then there’s the lovely ‘Helen Dawn’, which grows to 90cm and is a ghostly pure white that shines in the moonlight. It has a white beard that is yellow at the tip, deepening to almost orange in the throat and with a heavy, sharp scent.
If you want a shorter variety to sit close to the edge of a border, then check out ‘Green Spot’, which only grows up to 25cm tall. It has attractive olive-tinted white flowers with a green ‘thumb print’ and looks stunning when planted alongside bronze-leaved wispy fennel, the bold foliage of euphorbia wulfenii and purple salvia.
If you’re a real iris enthusiast, you should also check out the recently rediscovered vintage irises bred by the acclaimed artist and plantsman Sir Cedric Morris in the 1940s and 1950s.
These delightful flowers were almost lost to cultivation until Sarah Cook, head gardener at Sissinghurst until 2004, made a chance discovery of his iris ‘Benton Nigel’ in one of the old borders.
The French nursery Cayeux, specialises in the frilly and flamboyant iris and always has something new or special to offer.
One of the recent favourites is Iris ‘Poivre Rouge’, which has bright yellow blooms, decorated with red-brown striations and red speckles at the bottom of the falls, and ‘Cigarillo’, that also demands attention with its unusual copper-honey-toned blooms with orange bracts and generous branching up to 10 flowers per head.
To succeed with these glorious plants find them a spot that sees lots of sunshine and has well-drained soil. Plant them, 30-45cm apart, with the rhizome (thickened horizontal stem) half exposed and with the flat side of the leaves facing the direction in which you’ll view the flowers.
Finally, remove spent flowers to tidy up the plant and encourage more blooms, and in winter, cut the dying leaves back for neatness and to discourage slugs.