Some irises can be moved now

Press, 12 September 1986, Page 15

Some irises can be moved now

vOardener’s W DIARY

Derrick Rooney

Irises have been my preoccupation in the garden in the last week, because now is the time, if you missed your best shot last February, to lift and divide most of the non-bearded irises with which you want to make new clumps. Bearded irises can also, at a pinch be lifted now but to do so will almost invariably mean sacrificing a year’s flowering plus, probably, most of the year’s increment. If you are not sure whether it is safe to move a particularly iris, here is a little trick that can help you to decide; poke around the outside of the clump with a small trowel, gently scraping back the soil from the rhizome, and check whether the iris has new, white roots. If it does, and the new roots are no more than about 6cm to Bcm long, the plant may be moved. This advice applies to most of the commonly grown types of irises, such as the Siberians, the spu-

—rias, the Evansias, the Higo types, and the Louisianas. A few, such as the Pacific Coast hybrids, may be safely moved as clumps but resent being split up -(best to raise these from seed if you want new ;,ones), and a very few, ,such as the lovely Iris T kernerana, resent any . kind of disturbance at all. Bulbous irises may be moved, as clumps, just as, or after, the flowers fade but should not be dried off until the leaves turn yellow. Most iris species are fairly easily raised from seed, and flower in two or three years. Ideally the seed ought to be sown in autumn so that it can stratify over winter, but if, like me, you have felt disinclined to be out sowing seed in the cold, wet season just passed it is probably not too late now. I have quite a lot of iris seed to sow this week-end. One is the extraordinary Iris graebneriana, which grows 30cm tall and has bluish mauve flowers. Originally collected in Turkestan and cultivated for many years,

this is a Juno iris — one of a group of bulbous irises which carry double insurance against summer drought; they have conventional bulbs with large, fleshly, permanent storage roots underneath. They come from the semi-arid areas of Central and Western Asia and have sheaves of leaves like sweet corn, among which the modest flowers are tucked. Mostly they are quite easy to grow as long as they get a good summer “baking," but they prefer to be grown in the ground, rather than in pots. They transplant easily when dormant but it is a good idea to try not to damage their storage roots; they will probably survive damage, but will be weakened and may not flower again for a long time. So distinctively different are these from the general run of irises that they are sometimes placed in a different genus, Scorpiris. About 60 wild species are known, but as most of their habi-tat-is now out of bounds to Westerners or infidel only a handful are grown in gardens. The best known are the lovely sea-green, winterflowering “Sindpers,” and the white-and-yellow Iris bucharica, which flowers in October, often only a few days after it first pokes its nose through the ground.