THE NURSERY-LIST 427 



special strain or race has been developed ; seeds started in Septem- 

 ber give blooming plants before Christmas if the growing conditions 

 are right. See Lathyrus. 



Sweet Potato (Ipomoea Batatas). Conwhulaceoe. 



Sweet potato plants do not seed; they are grown in hotbeds, 

 coldframes or forcing-houses (depending on the latitude) from sound 

 tubers of medium size. The tuber is laid on a sandy or other loose 

 bed, and is then covered with sand or sandy loam to a depth of 1 or 

 2 inches. Sometimes, to guard against rot, the tubers are not 

 covered until the sprouts begin to appear. The tubers may be laid 

 thickly on the bed, but they are less likely to rot if they do not touch 

 each other. Sometimes the tubers are cut in two lengthwise, the cut 

 surface being placed down, in order to place all the plant-giving 

 surface uppermost. In four or five weeks the young plants 3 

 to 5 inches high are pulled off and planted, and others soon arise 

 to take their places. One hand should be held firmly on the soil 

 over the tuber, while the sprout is pulled off, to keep it in place. 

 Three or four crops of sprouts may be obtained from each tuber. 



Sweet William (Dianthus barbatus). Caryophyllaceoe. 



Raised from seeds, sown indoors or in the border, and by division 

 of the plants. Best results are obtained by starting new seedlings 

 every other year. 



Symphoricarpos (Snowberry. Indian Currant). Caprifoliacece. 



Propagated by seeds, handled like those of blackberries ; also by 

 suckers, divisions and both hardwood and greenwood cuttings. 



Symphytum (Comfrey). Boraginacece. 



Increased by seeds and by division ; also easily by root-cuttings. 



Symplocos. Symplocaceoe. 



Propagated by seeds, cuttings of green wood under glass, and 

 layers. Seeds usually germinate the second year. 



Syringa (Lilac). Oleaceoe. 



New varieties and stocks are grown from seeds, which are usually 

 stratified until spring ; and the main specific types are sometimes 

 grown in quantity this way. Green cuttings, handled in frames 

 in spring and summer, are largely used. Cuttings of mature wood 

 will grow ; also cuttings of the roots. Layers and suckers are often 

 employed. Varieties are extensively grafted or budded on privet 

 (Ligustrum) and common lilacs. Flute-budding is occasionally 



