14 



Conditions of this nature are almost invariably present during the 

 months of August and September. The da^^s are long and usually 

 hot and dry, followed, as a rule, by cool, moist nights. The plants at 

 this time are subjected to extreme changes, viz, from the hot, dry 

 atmosphere during the da}", which frequently causes them to become 

 wilted and remain so for several hours, to the cool, moist atmosphere of 

 the night, which causes them to become excessiv^ely turgid. Conditions 

 of this kind induce a I'apid, weak, soft, or succulent growth of the plants 

 which is particularlj' subject to disease and at the same time favors the 

 germination and development of the spores of the fungus. It is at 

 this season of the year, as a rule, that the spot disease is most abun- 

 dant and destructive. This is the time for great vigilance, and every 

 condition influencing plant growth must be made as favorable as pos- 

 sible to a hardy, health}^ growth which will be able to withstand the 

 attacks of disease. The grower who is able to accomplish this and 

 tide his plants over this critical period of their growth in a compara- 

 tivel}' healthy condition is fortunate, and, as a rule, has little to fear 

 from the disease during the remainder of the season. 



Artificial conditions include those wholly or in part under the con- 

 trol of the grower. They are too often neglected, resulting as a rule 

 in disease and consequent loss and discouragement. They may be 

 enumerated as follows: 



(1) Not keeping the houses or frames clean, fresh, and sweet by 

 frequently repairing and painting them and b}^ removing and destroj'- 

 ing rubbish of all kinds as soon as it appears. 



(2) Not keeping the plants clean and in the best possible growing 

 condition at all times. 



(3) Not selecting stock from strong, vigorovis plants that have been 

 entireh' free from disease. 



(4) Not being careful to select only strong, vigorous, healthy stock 

 from the cutting bed for planting in the spring. 



(5) Not giving the proper attention to the selection and preparation 

 of the soil, to the date and method of planting, and to the care and 

 cultivation of the plants during the growing season. 



(6) Not giving due consideration to the several varieties and their 

 adaptability to the soil and location in which they are to be grown. 



SUSCEPTIBILITY OF VARIETIES. 



While the susceptibilit}" of the plant to disease depends largel}' upon 

 the way in which it has been grown, still, as a whole, some varieties 

 are more susceptible than others; Marie Louise, for example, even 

 under conditions most favorable to growth, is more subject to injuiy 

 from spot than is Lady Hume Campbell. The former variety can be 

 grown to perfection only under the most favorable conditions, but 

 when thus grown it has no equal for size, color, and excellency of flower. 

 The hardier, more resistant, and more prolific variety Campbell stands 



