S6 THE CULTURE OF POT-PLANTS 



Sweet Pea (Dwarf) and Sweet Sultan. — For culti- 

 vation, see Annuals in Pots, p. 27. 



Tulip. — Several varieties are sweet scented, notably 

 Yellow Prince. For cultivation, see p. 145. 



Wallflower. — The double varieties are very fine, and 

 last for a long time in flower, but for fragrance the singles 

 are to be preferred. The seed may be sown in pots in May, 

 and the seedlings treated as advised for mignonette ; but the 

 plants will be stronger if sown in the open ground, trans- 

 planted once or twice to prevent them making taproots 

 (which could not be got into an ordinary sized pot and tend 

 to make them tall instead of bushy), and potted in September. 

 They^ should then be brought indoors, shaded for about a 

 week, and then placed where they will have plenty of light 

 and air. At all stages firm soil is necessary to keep their 

 shoots hard and short jointed. As the result of excessive 

 damp or any other condition unfavourable to growth, they 

 are sometimes attacked by rot, a leaf disease resembling 

 mildew. If it is merely a slight whitening of a leaf or two, 

 spraying with a very weak solution of permanganate of potash 

 may stop it ; but if the shoots are damaged, the affected plants 

 should be burned in order to prevent the infection of the 

 others. 



Violet. — See Viola odorata, p. 77. 



