February 1, 190S 



HORTICULTURE 



133 



Chrysanthemum Mildew 



Under extra culture the chrysanthemum is rather 

 ) ree from disease but under poorer conditions is subject 

 to attacks of rust, anthracnose, two leaf-spots, and a 

 |)Owdery mildew probably Erysiphe Cichoracearum, by 

 name, which attacks the leaves. In one greenhouse in 

 this vicinity the latter is quite bad, and as others may 

 l)e troubled with it either now or in the future a short 

 description may not be amiss. 



All mildews have tw-o stages; (1) the Conidial, or 

 summer stage when white or colorless "spores" are pro- 

 duced which propagate the disease over summer; and 

 (2), the Perithecial, when the brown or black spores 

 are formed which carry it over winter. The first is by 

 far the less serious, and that is the only one so far as 

 known, occurring on the chrysanthemum under glass. 

 Hence with a little care the trouble, even when quite 

 e.xtensive, can be eradicated easily. 



Certain kinds of chrysanthemums seem much more 

 susceptible than others. Col. Appleton being an example. 

 Other varieties as Ivory, Major Bonnaffon, and Timothy 

 Eaton, growing alongside of Col. Appleton badly dis- 

 seased, were not affected. The characteristics of the 

 disease are irregular white, woolly spots on the upper 

 surface of the leaf made up of fine filaments (the my- 

 celium, or growing parts), visible to the naked eye. 

 When very severe, the spots coalesce and the leaf ap- 

 peares as if it were dusted with flour, and when as bad 

 as this may appear on the lower surface. Under the 

 lens or microscope the spots are sliown to be colorless, 

 cellular threads, with immense numbers of colorless 

 oval bodies, the conidiophores, corresponding to seeds in 

 higher plants. 



Treatment. Plants grown entirely under glass are 

 not liable to contract the disease. It is while they are 

 growing out-doors that they become inoculated with the 

 fungus. If strong, vigorous stock is grown the cliances 

 of attack are considerably lessened. For plants already 

 affected sprinkle powdered sulphur (flowers of sulphur) 

 over the diseased parts when they are dry, or if in the 

 greenhouse, evaporate sulphur on the heating pipes. 



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Peaches Under Glass 



Editor of HORTICULTURE. 



Dear Sir: — I have a house of peaches. I do not know 

 this variety. How should I force them so as to get them 

 ripe about June, or earlier? Also Cardinal, Alexandra 

 Noblesse, Early Rivers, Thomas Rivers. 



lYours truly, G. F. 



If nothing has been done to the trees they should be 

 pruned and cleaned at once and tied up. Take off the 

 top soil about two inches and apply a good top dressing 

 of bone meal and cow manure and cover this over with 

 soil. Give the border a thorough watering three days 

 in succession and be well satisfied that the border is 

 wet through, else when the sap begins to flow the buds 

 will drop off. 



Keep the temperature at 43 degrees to 45 degrees at 



night, 45 degrees to 50 degrees by day fire heat, and 

 55 to 60 by sun heat. Care must be taken to start 

 them slowly. Syringe the trees and dampen the floor 

 four times a day until the flowers open. When they 

 are in flower keep tlie house dry. Shake the trees three 

 or four times a day to set the fruit. When set raise 

 the temperature to 50 degrees at night and correspond- 

 ingly by day. 



Thin fruit when the size of marbles, raise the tem- 

 perature to 55 degrees to 60 degrees at night and do 

 not increase the night temperature until they have 

 stoned; then it can be increased to 60 degrees to 65 

 degrees at night. When the fruit begins to ripen give 

 all the air possible day and night and withhold water 

 from the roots and trees, which will give them a higher 

 flavor. 



Early Elvers and Cardinal should be ready by the 

 first of June if started at once. The most important 

 things in raising peaches are to start with a low tem- 

 perature and increase it gradually; have the house and 

 vines clean; never allow tlie foliage to be wet after 

 sundown ; syringe tlioroughly on every favorable morn- 

 ing ; give abundance of water when fruit has stoned, and 

 withhold water when they begin to ripen and give 

 ]ilenty of air day and night when ripening. 



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Asperula 



When in flower Asperula longifolia is so much like 

 Gypsophila paniculata that the writer has known many 

 gardeners to take the former for the latter at first sight. 

 Unfortunately Asperula longifolia is not so well known 

 otherwise it would become just as popular. These 

 beautiful hardy plants come into bloom a few weeks 

 earlier than gypsophila which makes them all the more 

 valuable and with the well known stevias for winter 

 flowerinET their most useful flowers can be had for 

 decorative work almost continuously throughout the 

 year. Asperula longifolia, A. hirta, A. Arcadiensis, 

 A. Carpathica are the only ones of particular merit in 

 this family and ought to be in every hardy plant col- 

 lection. A. Arcadiensis is a charming little plant for 

 the rock garden and also for hanging baskets. The 

 flowers are pink and about one inch long with dense 

 wooly foliage and it is the most attractive of the dwarf 

 species, particularly when grown under glass. As a 

 general rule most of the asperulas are increased by di- 

 vision. A. Arcadiensis is such a slow growing species 

 that cuttings are recommended. The asperulas men- 

 tioned here are all in commerce and can easily be se- 

 cured. They will grow well in any ordinary garden 

 soil. 



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