252 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



tribe. Exactly why and how the fungus forms and spreads in a circle it 

 is not now necessary to enquire : we all know the fact that it does so and 

 that the Grass grows ranker and darker where the fungus is present. A 

 dressing of slaked lime at the rate of 2 tons to the acre, or of basic slag 

 at 1 ton to the acre, is a good remedy. Either of these will gradually 

 cause the rings to disappear, though it will often be necessary to apply 

 the dressing in two consecutive years. Of the two, basic slag is probably 

 preferable, although it is a little slower in its action than the lime is. 

 April is a good month for dressing the Grass, choosing showery weather 

 so as to wash it in to the roots. 



Silver Leaf. 



A correspondent sends us shoots of Peach and Plum affected with 

 Silver-leaf disease. The trees are growing in an unheated orchard 

 house ; they are about seven years old, and only four of them are at 

 present attacked — last year it was only two of the Peaches, this year two- 

 of the Plums have followed suit. The rest of the trees appear quite 

 healthy, nor has the disease as yet appeared out of doors. Sulphur has 

 been tried, but without any useful efiect. The gp^rden in question is said 

 to be very isolated, and until last year no sign of the disease had been 

 noticed. The gardener at first thought that a superabundance of lime in 

 the soil was the cause, as he recently had given a top-dressing which had 

 contained a good deal of lime ; but on hearing of a garden on soil abso- 

 lutely devoid of lime sufiered terribly from the disease, he has abandoned 

 this view of the cause. 



The fact of the matter is that the Silver-leaf disease is at present a 

 puzzle. It attacks all trees of the Prunus tribe — Peaches, Plums, 

 Portugal Laurels being the most notable victims. It is called Silver-leaf 

 because it gives a silvery or ashen appearance to the surface of the leaf, 

 and this seems to be caused by a separation having taken place between 

 the outer skin of the leaf and its green inner substance and a thin film 

 of air having got in between them ; but what has caused this separation to 

 come about is at present unknown. It attacks trees in apparently 

 robust health just as much as the weaklier members, fixing itself 

 first on one twig or bough and then on another, until at last it kills 

 the whole tree. The only cure is to kill. Up with the tree, and for 

 safety sake burn it root and branch — though there is no sort of evidenc3 

 that the disease is infectious, in fact rather the opposite, still it is well to 

 make sure. xV young tree may be planted, as we have proved, at the same 

 spot and not catch the disease. Gardeners would be most grateful to 

 scientists if they could discover the cause and the cure of this trouble. 



Vine Borders. 



A Fellow -^Tites asking whether it is necessarv to have outside borders, 

 and what depth they should be. He is advised that it is certainly better 

 to build the front wall on arches and have both inside and outside borders, 

 even if the outside one must (as in his case) be narrow. Two and a half 

 feet is sufficient depth for the border, and if 6 inches of broken bricks or 

 rubble is spread over the bottom and over the drain it should give 

 drainage enough. On the broken bricks or rubble lay turfs with the 



