1921, Lime and the Bearded Iris
The Garden p.301, June 18, 1921
Lime and the Bearded Iris. At the Iris Conference which took place last week a number of points relating to the successful cultivation of the Bearded Irises came under discussion. A few of them should be referred to for the general good. It is well known that lime is essential to the well-being of these Irises. Practically all the species are found growing on limestone formations. It was pointed out by Mr. W. R, Dykes that the bacteria which are responsible for the rot disease of the rhizomes multiply amazingly in lime, and consequently if there is evidence of this trouble ordinary lime should not be applied to the surface of the beds. Superphosphate of lime, on the other hand, is fatal to these bacteria, and a top-dressing will generally stop the mischief. If the plants are badly attacked it is recommended that they should be taken up, all the affected parts cut right away the cut portions being rubbed with superphosphate, and the plants given a fresh site. Irises will not flourish in a waterlogged position. If the soil is heavy the beds should be elevated above the normal level or even thrown up in banks so that efficient drainage is secured. The best time for planting is shortly after flowering, July perhaps being the safest month, as new roots are then being emitted. The plants are thus able to take firm hold of their new quarters before winter.
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