CHAPTER VII 

 PLANTS GROWN FOR THEIR SCENT 



It is not always easy to decide whether a plant is grown 

 for the scent or for the beauty of its flowers. In some 

 cases — for instance, mignonette and the rose Frau Karl 

 Druschki — there can be no doubt ; but others, such as sweet 

 peas, present more difficulty. The question is complicated 

 by the fact that while a plant may have a strong scent 

 under certain conditions, it may under others have little or 

 none. Mathiola bicornis loses during the hours of daylight 

 the powerful perfume which it emits at night; hence its 

 popular name, night-scented stock. This is true of many 

 other plants. Indeed, there are few, if any, which are not 

 more strongly scented after sunset than before. 



This might suggest the idea that, to get the greatest 

 benefit from them, they should be grown in the shade ; but 

 the majority are of tropical or subtropical origin. The 

 scent which they emit at night seems to require for its 

 elaboration heat and strong sunshine during the day. There 

 are two British species of mignonette {^Reseda lutea and 

 R. luteold)^ but both are odourless. For fragrance we must 

 go to the North African species, the cultivated mignonette, 

 and it loses some of that quality when it is grown in com- 

 paratively cold weather and when it is sown outside, say, early 

 in April instead of in May or June. Even violets are not 

 exceptional. It is true that in very hot positions in summer 

 they are certain to be infested with red spider unless they 

 are kept moist — often a difficult matter — but it is a mistake 

 to grow them entirely in the shade. They should be in 

 full sunshine in autumn and winter. 



Space does not allow of enumerating all the sweet- 



