Oncocyclus Irises--The Lime Theory by Jenkins
The Garden p.361, November 21, 1903
ONCOCYCLUS IRISES. THE LIME THEORY.
Doubtless the fact will still be fresh in the minds of many readers of The Garden that the late Rev. Henry Ewbank was personally superintending the replanting of his large collection of Cushion Irises in his garden at Ryde when he died. As the replanting at the time referred to embodied some important experiments, the work was carried out in the most systematic way. Of the way itself some details have already been recorded. These experiments amounted to an attempt to cultivate the Oncocyclus Irises more successfully than hitherto by the addition of lime to the soil in which the plants were growing. Some earlier partial experiments or studies of Mr. Ewbank in England were responsible for this, and, again, by Van Tubergen, jun., of Holland, who had specially sent a collector to the native habitats of these plants with strict injunctions to secure some soil in which the plants were found for the express purpose of analysis. And it was indeed while Mr. Ewbank was debating upon the lime theory that the intelligence was received from Holland that "lime" was really' the missing link and the chief secret in the successful cultivation of these plants. It is noteworthy that neither Mr. Ewbank nor M. Tubergen was aware of the conclusions the other had arrived at. That this was so, and the greater, broader fact that the conclusions of both gentlemen were in the main and for practical purposes identical, gave considerable colour to the lime theory. Mr. Ewbank was most -enthusiastic, and in one of his characteristio letters he regretted that he had not arrived at the same conclusions twenty years before.
I was, however, less firmly convinced, and gave Mr. Ewbank instances of good cultivation where
"the lime theory did not apply. I further pointed out at the time in The GARDEN that it was remarkable if the lime theory was to prove the all in all that someone gardening on limestone or chalk had not long ago revealed the fact. However, Mr. Ewbank planted one set, and in another set followed the directions received from Holland. That everything that the planter could possibly think of no one knowing Mr. Ewbank's intense admiration for these flowers will for a moment doubt. It is, therefore, the more unfortunate in these circumstances to have to say the lime theory is practically a failure.
Since Mr. Ewbank's death I have visited the old Parsonage Garden at Ryde, not always at the same season of the year, and have made an inspection of these Irises, but they have not done what it was expected of them ; indeed, in very few instances are any of the kinds forming tufts, I. iberica alone excepted. Many of the Regelia forms are highly satisfactory, and in fine tufts. It is, however, well known how less exacting are these beautiful forms generally. I believe I am giving simple justice to Mrs. Ewbank's gardener at Ryde in saying that these Irises have been cared for and attended of late in the old systematic way and with the same ungrudging care. Had Mr. Ewbank been spared to see as we have seen, he would long ago have made it known that the experiment was a failure. In these circumstances
For more information on historic Irises visit the Historic Iris Preservation Society at