This section is from the book "Beautiful Gardens - How To Make Them And Maintain Them", by Walter P. Wright. Also available from Amazon: Beautiful Gardens: How To Make And Maintain Them.
The Iris cult spreads apace. Every year finds the number of Iris lovers increase. We actually hear of Iris gardens. Let us, if a little startled at the outset in hearing of a garden being given over wholly to Irises, hasten to concede that the owner displays at least as much good taste and wisdom as he who gives up all his time and space to Dahlias, or Potatoes, or "Geraniums."
Fig. The Iris Garden At Kew.
After all, why not an Iris garden? Why not, at all events, an Iris garden within the garden? People are beginning to discover that there is a great charm in having gardens within gardens. Instead of great blocks of staring beds they divide the garden up with belts of shrubs, hedges, and arches into a series of secluded enclosures, opening into each other by winding, flower-bordered paths. In each enclosure some good flower is specialised, in greater or smaller quantity, as space and means permit. Consider the pleasure of walking round such a series of "inner ring" gardens. There is no blare of noisy colour anywhere. There is no desolating monotony. The senses are stimulated with the idea of boundless space. Pleasant hours pass in perambulating an acre. First there is the Rose garden, with its glowing arch of Crimson Rambler, at once herald and sentinel. Then there is the Carnation garden. The Lily garden follows. And presently, by perfumed, flowery paths, we come to the Iris garden.
Whatever be our leaning towards any particular flower, the Iris will challenge it. If we ask for beauty and variety of form, the Iris gives us both in ample measure. If we ask for richness of colouring, we see it in the Iris in a degree almost unexampled amongst hardy flowers. Fragrance we get, too, if not in every species. Above all, there is in the Iris that indefinable thing called charm. Our interest and affection are coaxed out of us almost unconsciously.
Every garden, then, must have its Irises. If only the cheapest, most easily grown sorts can be managed, we shall go for our material to the "Flags" and the bulbous English and Spanish. There are few cheaper plants than these; there are few more simply cultivated; assuredly there are none which yield such grace of growth and beauty of colouring. Given more ample means and leisure, we shall turn our attention to choicer species and hybrids. For some, requiring special treatment, we shall make separate provision. We shall introduce certain lowly gems to the rockery, and a few we shall grow mainly in frames.
It may be well to take a bird's eye view of the great genus Iris, in order that we may get an idea of the nature of the material at our disposal. And to begin with, we will make ourselves acquainted with the fact that the Irises are divided into two great sections - those with long, creeping rootstocks, called rhizomes, and those with bulbs. The former are termed the Irises proper, the latter Xiphions. A familiar example of the first section is the common Blue Flag or German Iris, and the second the Spanish.
If the rhizomatous Irises included none besides the Flags they would still be a large and valuable class, for its varieties are numerous, extremely diversified in habit, and of most beautiful colours. The Flags are sometimes themselves divided into sections - the bearded and the beardless. But there are many other rhizomatous species, and in some instances they expand into quite large and important sections, such as the Cushion Irises.
The species include many beautiful plants, among which may be mentioned aphylla, cristata, Florentina, Germanica, laevigata (Kaempferi, the famous Japanese Iris), pumila, Sibirica, squalens, and variegata. Of most of these there are several varieties.
In the Cushion Irises we find such beautiful and interesting things as Bismarckiana, Gatesii, Iberica, Korolkowii, Lortetii, and Susiana (the Mourning Iris). As a class they are not nearly so hardy and accommodating as the Flags, requiring light soil and warm positions, together with protection from heavy rain in some cases. But such gems as Gatesii, Lortetii, and Bismarckiana are worth much more trouble than they cause.
When we turn to the second great group - the Xiphions - we find an equal wealth of material, comprising some of the most delightful Irises grown. Leaving altogether out of account for the moment the scores of beautiful varieties of the English Iris (Xiphioides), and the Spanish Iris (Xiphium), which are a host in themselves, we have still left such Irises as alata, Bakeriana, Histrio, Persica and its beautiful variety Heldreichii, reticulata and its varieties (of which Krelagei is one of the best), Danfordiae, and Rosenbachiana.
The flower lover who wants bold effects from Irises, particularly if he lives in or near a town, will be wise to devote most of his attention to the Flags. These will grow almost anywhere, and their thick masses of long, narrow leaves, tall stems, and huge flowers are very impressive. With occasional division and transference to richer soil, which may be done at almost any time from August to spring, they will thrive for many years. They may, of course, be grown in herbaceous borders.
Equally dominating are the Japanese Irises, varieties of laevigata, but these will not succeed, like the Flags, in dry places. They love root moisture, such as they get at the waterside. When well suited they grow to an enormous size, and the spreading, flattened, richly coloured flowers are as large as dessert plates. Another moisture loving Iris is the common hardy, yellow species Pseudacorus, known as the Water Flag.
The Cushion Irises will prove an abundant source of interest. The lover of these beautiful plants will find a sunny, sheltered spot for them, where they will have protection from cold winds in spring. He will endeavour to procure some good, light loam, well disintegrated with abundance of sand if at all adhesive. He will fix small squares of glass over them to ripen them after flowering. And if the position is at all cold he will spread reeds or light litter over the beds when winter approaches.
Pumila, and other dwarf species, are well suited to the rockery. Sibirica, a graceful though not showy plant, thrives on heavy, well-worked clay; it loves moisture. Unguicularis or stylosa, Danfordiae, and some others flower in winter, and must have shelter when in bloom, or the flowers may be spoiled by frost. The lovely, perfumed reticulata and its varieties are also winter bloomers, and owing to their liability to injury when in the open air are frequently grown in pots in frames.
Nearly all the Irises may be planted in autumn or early winter, but the Cushion Irises are best kept out of the ground until December, as if planted earlier they are liable to make growth which is cut by frost. English and Spanish Irises can be bought with the Dutch bulbs in October, and they are as cheap as most. But it must not be supposed that because they can be purchased for a few shillings a hundred they are not worth growing. They are really beautiful for late spring and early summer blooming. They are good in the mixed border, and make excellent beds. They do not need frequent disturbance.