ON THE CULTURE OF ERICAS. 203 



ARTICLE IV. 



ON THE CULTIVATION OF ERICAS. 



(Continued from page 178.) 



If there be no appearance of a change, then it is necessary to 

 apply heat to the house ; but all that is wanted in this case, is just 

 enough to prevent the temperature from getting lower than it was 

 when the heat was introduced. Suppose the thermometer to sink 

 to eighteen or twenty degrees below freezing during the night ; the 

 instrument inside should range as near as possible to what it was 

 when the heat was applied. This however requires very par- 

 ticular attention. From what I know, heaths will suffer, if, 

 after the thermometer has fallen four or five degrees below freez- 

 ing inside of the house, heat be added so as to raise the tempera- 

 ture, and drive out the frost, during the time the thermometer 

 is still sinking out of doors. It would be much better if the 

 house were left without fire heat, even with the thermometer 

 fifteen or sixteen degrees below freezing point out of doors ; such 

 treatment is bad for all plants, but more particularly for heaths. 

 If we were certain that the thermometer during the night would 

 not sink more than ten or twelve degrees below freezing out 

 of doors, no artificial heat whatever would be necessary in 

 the heath house." 



I have made this long quotation, because it is the tried practice 

 of one of the best cultivators of the present day ; and if acted 

 upon, will remove much of the cultivator's anxiety, so far as the 

 true principle of applying artificial heat is concerned, and convince 

 him how small a degree of that element is really necessary, in 

 greenhouses of the ordinary descriptions. 



During winter, water should be very sparingly applied to heaths 

 and in times of severe frost only enough should be given to keep 

 the plants from drooping. The case is different however, during 

 spring and summer, when they should have it abundantly supplied 

 once, and, in some cases, twice a day, at their roots, and two or 

 three times during the week over their leaves and branches by 

 using the syringe or small garden engine. 



Cape heaths are very liable to be attacked by mildew, particu- 

 larly in the neighbourhood of London: and some collections have 

 been nearly destroyed from this cause. Sulphur, applied either 

 in a dry or moist state, is the most effectual cure, and should be 



