The Garden p.541, November 11, 1911
There are always two seasons in the year during which any group of hardy flowering plants may be usefully referred to with benefit to the general body of readers. These are naturally the flowering and the planting seasons, and in selecting the latter at the present time I do so in the hope of making better known the above-named modem race of hardy hybrid Irises. It was in the spring of 1904 that Mr. Hoog (Messrs. C. G. Van Tubergen, jun.) brought from Holland the earliest varieties of this new race to the old Drill Hall, Westminster, and the warmth of the welcome they received, as also the enthusiasm that prevailed, must have been a source of considerable satisfaction to the originator of the new set. At that time these new Irises brought with them a reference of seven years' standing at once a record to perfect hardiness, to free flowering and amenability to conditions of cultivation that are simple in the extreme.
The reader should be told at once, I think, that the new race had been evolved by the intercrossing of the finest of the Oncocyclus or Cushion Irises with those of the Regelia group, the object in view being to embrace as much as was possible of the hardy, enduring perennial character of the last-named set, and to endow the progeny with as much of the fascinating beauty of the Cushion race as circumstances rendered possible. How successful those efforts were may be gathered from the fact that at a single sitting on that memorable day in May, 1904, the floral committee of the Royal Horticultural Society made some six or seven awards to the newcomers, three of these being of the "F.C.C." standard. That the committee were fully justified in this, subsequent events have proved unmistakably; and the fact that these Irises had proved so generally hardy in Holland was accepted as a good omen for their behaviour within the limits of the British Isles. That there was room for such a race, those who had endeavoured to cultivate the true Cushion Irises and failed signally again and again knew full well ; and even though the newcomers did not embrace all that quaint or picturesque beauty so characteristic of the Cushion race, they were certainly endowed with attributes e.g., growable plants of perennial duration the others did not possess. Hence there was room for this new hardy hybrid set, and being totally unlike others then existing, the varieties were quickly in demand.
The Cushion Irises proper, of which I. susiana is one of the most distinct, have, as is well known, the tantalising habit of dying out when planted in the open garden, and only respond to cool greenhouse treatment within certain limits. With the coming of the new Regelio-cyclus race, however, on learning their parentage I entertained hopes that some of them at least might prove to be endowed with attributes fitting them for cultivation as herbaceous border plants. This was expecting too much, a consummation, however desirable, which has not been realised.
Indeed, while these new hybrids have inherited much that is good from both parents, and while they are richly endowed with vigour, perennial reliability and freedom of flowering, they have also inherited and display an unmistakable desire for a period of absolute rest and inactivity each year. This much, indeed, appears essential so far as the welfare of the plants and the climatic conditions of these islands or of Holland are concerned. It is a condition, too, judging by the freedom and continuity of the growth of the plants, that might prove not a little perplexing to the uninitiated, who, with the evidence of perpetual activity before him, might hesitate to do what is necessary or right in the circumstances. Indeed, such evidences as those we have in mind, and of which the plants, rightly cultivated, each year afford abundant proof, might well perplex even an expert cultivator, were it possible for the latter to disregard the likes and dislikes of the original parents in these matters. Hence a period of rest, absolute and complete and out of ground, is most essential to the permanent success of the group we have in mind. To cover the plants with hand-lights or cloches does not produce identical results, and nothing short of cutting off food supplies from the roots and root fibres will produce the desired effect. To secure this the plants should be lifted late in July or early in August and stored away in shallow boxes in any well-ventilated place till October is well on the wane. At that time and for a few weeks longer the plants may be put out in their flowering quarters, though nothing is gained by undue delay in replanting. The primary object of the enforced rest to which I have referred is to keep the growth in check till the worst of the winter weather has gone, beyond which the plants have little to fear save the insect foes common to most gardens. I have tried some of these fascinating Irises on a warm border minus the orthodox lifting and resting, and. as a result of its enfeebling effects, strongly advise all interested not to go and do likewise. Thus treated, the plants produced much early winter leafage, to which the unthinking slug paid marked attention. In the matter of soils I have found these hybrids to respond readily to those of a rich, light character. Bone-meal or old lime rubble mingled with the soil is much to their hking. ---E. H. Jenkins. Hampton Hill, Middlesex.
For more information on historic Irises visit the Historic Iris Preservation Society at