DIVIDE AND PROSPER

I read somewhere that the three most popular French flowering plants are the rose, the peony and the iris –and it is not hard to understand why, especially with the iris. This plant, in its many forms, can be found in flower all year round somewhere in France, but the species which grabs our attention, and which is just finishing a spectacular season of flowering is the bearded iris, or iris germanica, which gives its name to the French symbol the ‘fleur-de lys’.

Iris germanica is in flower from approximately April to June. It is evergreen with fleshy sword like leaves and six petals – three known as falls (the droopy ones) and three known as standards (the ones which rise up and almost meet at the top). Most distinctively, they have a yellow beard at the throat of the falling petal; hence the name. The design of the flower head is such that it is perfectly adapted to insect pollinatin – with the standards attracting the attention of the insects and the falls providing a landing stage for them to settle on. These often have rows of dots or lines guiding insects to the heart of the plant where the pollen bearing anthers and sticky stigma are hidden. The bearded section of the falls give the pollenating insect firm purchase as it moves into the flower.

The bearded iris is a staple of French gardens, especially in the South West where it thrives in hot, dry summer conditions and in the alkaline, or limestone, soils. The common-or-garden form is blue and there must be very few old established gardens in France which do not have a blue, bearded iris tucked away somewhere. Indeed – they can multiply at such a rate that they can become a menace in places. They should be divided about every three years and it can become a challenge to know what to do with the bits of rhizome (root) which you no longer have space for.

Over the years bearded irises in particular have been bred to produce a tremendous range of colours and combinations, to be short or tall and to have ever increasing degrees of flounce and frill to the petals. Personally I am fondest of the more simple shapes, where you can see daylight between the standards as you look at the flower head, rather than the highly ornate flower heads which are a mass of curly edged, multi coloured petals.

Specialist nurseries such as French grower Cayeau (www.iris-cayeau.com/ ) grow a spectacular range of varieties and last year these were some I saw at the show.

Chelsea irises

My personal favourites at the show were some wonderful tall, sepia tinted irises originally bred by artist cedric Morris at his garden, Benton End around 60 years ago. These have been revived by Sarah Cook, whowas a gardener at Sissinghurst in Kent. here she found a label for Benton Nigel, did some research and discovered dozens more distinctive irises cedric Morris created. She has since sourced and propagated many of them and I for one will be growing on some of her progeny in my garden in France. I am going to start with Benton Susan, not because it shares my name, but because it is my favourite colour, a willowy tea stained plant which contrasts so strongly with the louder, modern varieties which are more popular today.

Benton Susan

If you want to know more about what Sarah has done and how she achieved it, have a look at the following link:

http://www.telegraph.co.uk/gardening/chelseaflowershow/11545006/Chelsea-2015-Cedric-Morris-irises-return.html

Bearded irises may be past their best in the garden now, but the time to lift and divide them (and give some away or swap with friends) is imminent. Once the flowers die back the iris can be lifted, the leaves trimmed back to about 15 centimetres and the rhizomes (the fleshy tubers the growth sprouts from) can be divided into sections. Just snap them – they will break easily into chunks. If they are too rubbery to snap cleanly think twice about replanting them.

A present for me from Heather - the rhizome was transplanted last July

The rhizome is the food store, so divide each clump so that each individual piece has a firm, fat, fleshy section of rhizome with a spike or two of leaves sprouting from it and spidery roots on the underside. These can then be replanted separately in the same place or elsewhere in the garden. The important thing to remember is that the rhizome needs to show above the surface of the soil and it needs to be in a sunny, open position. If the iris is not baked by the summer sunshine it will not develop plenty of flowers the following year. This also explains why you need to lift and divide them every few years because their flower production declines rapidly if the plant becomes congested.

More flamboyance from Chelsea

The newly planted rhizomes are not easy to anchor, which is why you cut the leaves back – to stop the plant rocking in the wind. Tuck them into a little mound of soil and make sure those spidery roots are firmly under the soil surface - they will quickly settle down and establish themselves. If you divide them in July you should have a good crop of flowers the following spring. I have divided them at most times of year without actually losing the plant – but the later you leave it the less likely you are to get flowers the following season.