CHAPTER 23 



LILAC {Syringia vulgaris) 



Cultural Considerations. Indoor lilacs at first re- 

 quire a cool ho\ise. The temperature is gradually in- 

 creased to about 60 degrees. The plants require fre- 

 quent sjrringing and moderate ventilation. 



Diseases of the Lilac 



Forced lilacs are subject to a few diseases. The 

 plant is generally considered very hardy. 



Leaf Blight 



Caused by Pseudomonas syringe van. Hall. 



Symptoms. The disease as described by Gussow * 

 seems to be confined to the leaves. The writer has 

 found a blossom blight of the lilac both indoors and 

 in the field. In pure culture, the organism resem- 

 bled P. syringa. The affected leaves become greatly 

 disfigured; the disease spreads very rapidly. 



Control. It is doubtful whether spraying will be 

 of any avail. The plants should be given plenty 

 of ventilation whenever possible. Diseased leaves 

 should be destroyed by fire. As far as possible the 



* Gussow, H. T., Gard. Chron. 44: 404.-405, 1908. 



275 



