96 



Where the disease has once occurred, it is probable that the ground 

 near the diseased plants is covered with germinating spores. Hence 

 it is advisable to disinfect this ground with some such substance as 

 lime, applied in a liberal manner. Wood ashes applied copiously may 

 be used, and will act as a manure. Failing these, some disinfectant 

 may be applied with a sprinkler. For this purpose a concentrated 

 solution of sulphate of iron is useful, but the ground should not be 

 saturated with it, as that might injure the plants. Solution of 

 formalin may be used. Merely digging over the earth will do good. 



Bordeaux mixture is known to be an efficient remedy for this disease, 

 but it is rather out of place in a flower-garden, as the appearance of the 

 sprayed plants is far from attractive. Ammonio carbonate of copper 

 .and Eau Celeste are less objectionable, but they are not so effective. 



Where Hollyhocks have suffered severely it is well to start a new 

 bed at a distance from the old one. Eoot out the old bed and destroy 

 the stalks and roots, and then dig the ground well over and disinfect it. 



Diseases of the Rose. 



Black Spot. 

 [See Coloured Plate, Frontispiece.] 



There are at least two distinct diseases of the rose characterised by the 

 .appearance of blackish spots on the leaves. Of the two, the present, 

 to which the name " Black Spot " will be applied, is probably the more 

 common and destructive. Under the climatic conditions of the greater 

 part of this State it appears at all seasons, and is characterised by the 

 appearance on the leaflets of dark spots varying in size but seldom 

 more than a quarter of an inch across, except by the amalgamation of 

 several that have originated near each other. The normal form of the 

 spots is circular, and the first indication of their presence is the loss of 

 ihe normal green colour of the leaflet at the place where the future 

 " Black Spot" will appear. Though very inconspicuous, this symptom 

 is the most positive indication that the disease has secured a hold that 

 nothing can shake loose, for such a beginning must lead inevitably 

 to the formation of a typical diseased spot in spite of any remedy at 

 present known. The only preventive is to destroy the infected leaflet. 



From this small beginning the spot increases in size until it reaches 

 the dimensions described above, changing colour meanwhile through 

 dark brown or purple to almost black. Not infrequently a single leaf- 

 let bears scores of these spots, which most people would describe as 

 unsightly. Nevertheless, I must not forget to mention that I know 

 more than one person of artistic temperament that, on making up a 

 bouquet of roses, seeks out one or two of these diseased leaves for their 

 effect in the composition of the bouquet. I am compelled to admit that 

 the colouration of the diseased leaves is sometimes of an agreeable 

 nature, and that a leaf or two with picturesquely arranged spots, or 

 leaves that have taken on a bright yellow colour preparatory to final 

 dissolution, when skilfully disposed in a bouquet do give an added 

 charm, perhaps by way of contrast with the perfection of the roses 

 that droop above ; though I am almost afraid to admit such heretical 

 .statements into the literature of pathology. 



