Fragrant beauties

This week, it's our columnist's ireses that have put on a magnificent show
For many weeks, the lilac-blue fl owers of Iris pallida subsp. pallida, the Dalmatian iris, with their yellow and white beards, have been an elegant sight at the far end of the garden. Although each fl ower lasts only a day or two, there are so many on each stem that the overall flowering period is satisfyingly long.

I like their subtle fragrance, and although some gardeners profess to find them dull, prefer them to the more colourful hybrids. We are told that in order to flourish, bearded irises need their rhizomes to be baked by the sun. This most certainly did not happen last summer, so the magnificence of this year’s display seems yet another puzzling response by the plant world to our bewildering new weather patterns. They do need a well-drained soil and plenty of well-rotted organic matter in spring. Bearded irises will not flourish in shade, which suggests that they need light as much as direct sun.

After flowering, the stems of bearded irises should be snapped off near the base and dead leaves tidied where necessary. The rhizomes need lifting and dividing every two to three years. I tackle mine in September, splitting them up into fans of leaves with a rhizome attached. Experts advise cutting the leaves back to a ‘V’ shape, which makes up for any root loss and discourages wind rock. I discard older rhizomes and replant younger ones so that they face south for maximum exposure to the sun and with their roots at soil level.

Iris sibirica, the Siberian iris, is another favourite, slightly later to fl ower. It has narrow, strappy leaves and a profusion of blue-violet fl owers (a few varieties come in shades of pink, yellow and white). Unlike Iris pallida, which marches forth across a bed like a well-drilled platoon, established clumps of Iris sibirica form a circle after a while, with a bare centre. The clump needs to be lifted, divided and replanted. The leaves die back in winter. Iris sibirica is accommodating as to habitat, tolerating some shade and growing in any decent garden soil that is moist but not waterlogged.

The first to flower in my garden is I. sibirica ‘Ruffled Velvet’. This has deep purple flowers with a blackveined, pale yellow blotch at their base and ruffl ed centres. It is a magnifi cent sight, with lustrous leaves as well as velvety fl owers, and is defi nitely on my desert-island plant list. Other sibiricas that perform well are ‘Perry’s Blue’, a glorious sky blue, ‘Flight of Butterflies’, which has violet-blue fl owers with white veins, and the popular ‘White Swirl’, which has fl atter fl owers then most sibiricas, a lovely pure white with a yellow base.

If I can find the space (a fairly insurmountable challenge, bar moving to a larger garden), I would love to grow some of the Japanese water irises, Iris ensata (formerly known as I. kaempferi). They can be hard to track down but are listed by quite a few nurseries in the RHS Plant Finder 2013. They are usually sold as marginals for the banks of ponds or streams or for moist borders, but can also be grown in pots, which may be the solution to my space problem. The RHS advises standing the pots in shallow saucers kept topped up with water containing a little liquid fertiliser when the foliage starts emerging in spring. After flowering, the pots should be moved to a light, sheltered site to let the plants grow on, and should be kept moist. Japanese irises should be repotted in autumn in a gritty, fibrous compost, with a slow-release fertiliser, topped off with some well-rotted manure.

Before I go, I should just mention Iris ‘Jane Phillips’, everybody’s favourite tall bearded iris, with fragrant, pale blue flowers, a must in every cottage garden.

Contact Sarah at


Cayeux Irises: 0800-096 4811,
Claire Austin Hardy Plants: 01686- 670342,
Kelways: 01458-250521,