H orticulture: 



July i, 1905 



Rose Diseases 



II 



5. POWDERY MILDEW. (SPH.^ROTHECA PANNOSA) 



The powdery mildew develops ver}' rapidly on 

 plants, either in the greenhouse or outside. It is 

 well-known by nearly all growers and needs no ex- 

 tended description. The leaves appear to be dusted 

 over with flour. If left to itself the mildew will 

 eventually ruin its host. 



Treatment. Evaporate sulphur on a stove or by 

 painting on the pipes. A third method is to close 

 the house about eight o'clock, fill it full of sulphur 

 by means of bellows, then let the temperature run 

 up to 8g or 90 degrees, having it up to 75 degrees to 

 start with. Ventilate slowly after leaving long 

 enough for the sulphur to settle. Potassium Sul- 

 phide, one ounce to two gallons of water, makes a 

 good spray. 



Keep the plants in a healthy, thriving condition, 

 as mildew is brought on by lack of food, irregular 

 feeding, exposure to drafts, and heav}- waterings. 



6. BRONZING 



Grafted tea. Bridesmaids, and Bride roses are 

 particularly susceptible to a spotting or mottling of 

 the leaves, due to a physiological cause. The spots 

 are one-sixteenth to one inch in size, generally turn- 

 ing yellow, although not always, and the foliage 

 falls to the ground. Affected leaves are confined, 

 first, to where the stem is cut and a new branch 

 starts — the leaf at the l)ase is bronzed many times; 

 and, second, to leaves where the axillary bud be- 

 comes rubbed off. Small weak stock or stock mak- 

 ing a watery growth is very liable to bronze. The 

 spots have the same general characteristics of black- 

 spot. 



Treatment. Bronzing is of little consequence as 

 it usually occurs below the point where the flowers 

 are cut, but it might be mistaken for something more 

 serious, so is inserted here. There is no known 

 remedy. Give as good cultural conditions as pos- 

 sible and there will be little trouble from it. 



7. NEMATODES. (eEL WORMS) 



These microscopic worms cause enlargements on 

 the roots which are often taken to be disease. The 

 worms are abundant in warm climates and the 

 greenhouses offer favorable conditions to them. 

 They get in on plants, in soil, or in manure. 



Treatment. Examine all roses before planting and 

 destroy any showing root galls. Freezing will kill 

 many,' and sterilization is a sure thing. Lime 

 sprinkled on the bed or mixed with the soil will 

 destroy large numbers of them. Infection may take 

 place by growing plants, subject to nematodes, in 

 soil where infested plants were grown, as roses 

 planted where violets were raised, and so on. 



With the mention of another mildew, this article 

 will close. This is the Peronospora sparsa, a mildew 

 more penetrating and harder to find than the Sphas- 

 rotheca. Tlie treatment is the same as for the an- 

 thracnose. The disease does not exist to any very 

 great extent. 



Ornamental Horticulturists 



One cannot take up a trade paper without seeing 

 a photogra])h of the achievements of some "American 

 florist," in the shape of a house of some specialty or 

 another grown to perfection, or a "design," basket, 

 or spray, the work of some artist, that even with the 

 meager idea conveyed by the reproduced photograph 

 gains our admiration, but how seldom — and in this 

 case surely "the exception proves the rule" — do we 

 see pictured or written iip, the description of outside 

 work, that demands anything but a fleeting glance? 

 A visitor from abroad landing in Boston, and being 

 fortunate enough to bear the credentials that would 

 ensure his pilotage through the park system, and 

 some of the "show" places around the Hub, would 

 go away with a very exalted idea of the way "orna- 

 mental horticulturists" were conducting their work 

 in this vicinity. But let the same "foreigner" me- 

 ander at his own sweet will, and visit some of our 

 suburban districts, where rich people have made their 

 homes, and there would come a "change o'er the 

 spirit of his dream." 



Within the last few weeks, I have had the oppor- 

 tunity of seeing at close range some estates where 

 thousands of dollars have been expended, and the 

 return to the man footing the bills must have made 

 him v-ish that he had never met or entered into a 

 deal with a "landscape-gardener. " In some sections 

 the painful similarity of the planting is more than 

 noticeable, the only perceptible distinction being in 

 the size of the estate; and the placing of the different 

 varieties in a mixed bed indicated that the person 

 in charge was simply totally ignorant of the nature 

 of the species he was handling. 



As these last remarks may not be specific enough, 

 a few examples may be quoted. A glaring instance 

 that occurs to me was where a bed narrowed down 

 to an acute angle, said angle caused by two small 

 walks, and clear up into the apex of this angle was 

 planted weigelas that, to make room on the- walks, 

 had to be pruned back until they were mere stubs, 

 entirely destroying the beauty of the group. This 

 same fault of planting too close to the verge was to 

 be seen very frequently. Where groups of one vari- 

 ety were used they were planted too closely, and 

 where mixed beds were to be seen it was often the 

 case to find the tall subject on the outside of the 

 bed instead of being placed further in. The same 

 fault could be found with herbaceous beds and bor- 

 ders. No doubt in time these mistakes will occur 

 less frequently, for property owners are becoming 

 better acquainted with how their grounds ought to 

 be handled and are rapidly acquiring a knowledge 

 of the nature of many of the subjects used for the 

 beautifying of their estates, so that in the near future 

 the firms doing work in the loose manner described 

 will be forced out of the business. Fi-om inquiries I 

 carefully made I found that much of this work had 

 been done by chea]-) help and it certainly looked it. 



