PLANTING IRISES

Otago Daily Times, Issue 23707, 14 January 1939, Page 21

PLANTING IRISES

JUDICIOUS SOIL PREPARATION The November and Decemberflowering flag irises make most of their root growth after the blooms have faded. Because of this peculiarity, it is possible to transplant them at this time of the year with very good results. If plants are lifted now, it will be found that though most of the older roots look rather thin and feeble, a number of sturdy young rootlets will be pushing out from the thick fleshy rhizomes that lie along the surface of the ground A little later it will be impossible to dig up the plants without breaking many of these new roots, for they are very brittle, but just at the moment they are quite short and can be preserved intact, providing due caution is taken.

Do not attempt this work when the ground is very hard and dry, but wait until a few good showers have moistened it to a depth of several inches. Then lift the plants with a fork, and be careful not to tug them from above, or the young roots may part from the rhizomes. Let all the pressure come from below, and then, if it is intended to divide the clumps as well as transplant them, shake the soil from the roots carefully, ‘ or, if it sticks, tease it out with a pointed stick. The actual work of division can usually be done with the hands alone, as the rhizomes are quite brittle, and snap off easily. However, if any difficulty is experienced, a sharp knife can be used with discretion. STRONG YOUNG GROWTH IS BEST There is no point in keeping a lot of old and worn-out rhizomes. Usually the centre of an old clump gets so hard and dry that it is quite useless, and if retained, is only a drag on the plant, providing a good germinating ground for the spores which spread disease. In consequence, it is best to break the old

pieces off altogether. It is quite sufficient if each sturdy young growth is attached to a piece of rhizome, a couple of inches in length, and provided with a good tuft of roots.

Contrary to popular belief, flag irises succeed best in a sunny and rather dry position. They will tolerate a surprising amount of shade and moisture, and may even be seen dragging out an existence in the most impossible town gardens, but only in full sun will they give their best. Moreover, they like plenty of lime in the soil, and are particularly partial to it in the form of old mortar rubble. Consequently, if this material can be obtained cheaply, it is an excellent plan to'work in a liberal dressing when preparing the iris beds. Should the ground be at all heavy or inclined to lie wet in the \yinter, it is advisable to raise the beds a little so that water does not collect around the rhizomes in winter.

It is, of course, by no means essential to grow irises in beds by themselves, though the connoisseur usually prefers to have them in this way. But many owners of small gardens could not possibly afford the room for an iris border, and must, perforce, associate them with other herbaceous perennials. Even so, it is worth while preparing the sites individually, breaking up the soil as deeply as possible, and working in some lime and mortar rubble. Keep the plants well forward in the herbaceous border, so that they do not get smothered by other taller and leafier subjects. HOW TO PLANT CORRECTLY When planting, it is necessary to cover the rhizomes with soil, though their natural position is on the surface. If they were kept above ground from the start, however, it would be impossible to make them sufficiently firm, and the plants would blow over in the first high wind. Fortunately no harm results in a light covering at the outset as the rain soon washes this away, and leaves the rhizome top bare in its natural manner. Thorough firming is always necessary, no matter what plants are in question, but becohies even more important in the case of irises, because of the shallow planting necessary. If the soil is not pressed hard down with the foot on top of the rhizome and roots, there is sure to be trouble later

If the weather during January is showery, as it so often is, no watering should be necessary, but it is folly to allow the plants to dry out badly. Should it become essential to use the watering-pot, fit this with a fairly coarse rose, and then give sufficient water to soak the soil to a depth of several inches. Sprinklings will do more harm than good. Flag irises do not require a great deal of feeding, but they usually respond very well to an occasional application of superphosphate of lime. It is not wise to give this immediately after planting, as roits will not be in a fit condition to'deal with it, but a few weeks later, umen the irises are firmly established and new growth is being made, a very light dusting of superphosphate will help them along. A further and heavier application can be given the following spring, when the plants are forming their flower buds. Not only does the superphosphate stimulate growth, but it also has a marked effect in preventing rhizome rot, the on serious disease from which the flag iris suffers. A FEW GOOD KINDS There is not space in this article to deal exhaustively with varieties, but it may be as well, for the sake of the novice, to point out that such a vast amount of breeding has been done during the past twenty or thirty years that it is folly to plant old varieties if these have been completely superseded by more recent introductions. The very latest seedlings usually fetch prices which are prohibitive to all save specialists, but, after a few years, they can be propagated in sufficient numbers to meet the demand, and the price falls to a modest shilling or so per root. A study of the catalogue of any iris specialist will elicit a vast amount of information bn these matters, while the absolute novice can hardly do better than leave selection to the nurseryman. A good half-dozen for a start are: Ambassadeur, Souvenir de Madame Gaudichau, W. R. Dykes, Mystic, Mount Penn, and Imperator; but there, are dozens of _ other varieties of outstanding merit and modest price from which to make one’s own selection. —A. H,,. in Amateur Gardening.