200 



Commercial Gardening 



and will attain large proportions. Market growers, however, prefer them 

 in 5-in. or 6 -in. pots, and often cut the old ones hard back in the new year 

 to make plenty of new growth during the season. 



Petunia. The garden Petunias have originated from two South 

 American species, namely P. nyctaginiftora and P. violacea, the first 

 hybrid between them having flowered in 1837. Since then vast strides 

 have been made in the evolution of the Petunia by crossing and inter- 

 crossing, and, instead of having only single flowers about 2 in. across 



and of one shade of 

 colour, there are now 

 single and double forms 

 with flowers 4 to 6 in. 

 across, and with shades 

 of colour varying from 



t/ O 



the purest white through 

 rose, pink, purple, ma- 

 genta, crimson, and in- 



c^ ' ' 



termediate shades to the 

 deepest violet colours 

 relieved in many forms 

 with streaks, blotches, 

 and bands of totally dis- 

 tinct shades. Instead of 

 flowers with a simple 

 outline there are now 

 Petunias in which the 

 petals of the corolla are 

 beautifully cut, fringed, 

 crimped, and curled in 

 various ways (fig. 295). 

 Petunias are really 

 perennial plants, but it 

 is found more convenient 

 to treat them as halF- 

 hardy annuals. They 

 seed freely, and many choice strains exist. The dust-like seeds are sown 

 thinly on the surface of a nicely prepared sandy compost in February or 

 March in a temperature of 60 to 65 F. at night, and are kept in a fairly 

 moist condition. When large enough to handle easily the seedlings are 

 pricked out about 1 in. apart in shallow boxes or pans of light soil. In 

 April they will be ready for moving singly into 3-in. pots, or fine specimens 

 may be put into 5-in. pots for special purposes. In many cases, however, 

 the plants are simply transferred to shallow boxes, and are sold in the 

 young stage in this state. Pot plants usually have the tip of the main 

 shoot pricked out to induce bushiness, and by the end of May and in June 

 the trade is in full swing for bedding out. 



Fig. 295. Petunias (single and double) 



