340 THE PRINCIPLES OF FLORICULTURE 



mand for the callas. Commercially, they are frequently 

 grown in beds, using a very rich soil, and given full sunlight, 

 with an abundance of water, during the growing season. 

 Large flowers are the result. The plants are dried off as 

 summer approaches, and given a season of rest. As a pot 

 plant, the calla is frequently grown as a window plant 

 in dwelling houses, but unless the rhizomes are large, and 

 an abundance of pot room and rich soil are given, it is 

 rarely satisfactory. During the summer, the pots are laid 

 on their sides out of doors and in the shade of trees. They 

 are not allowed to become bone dry, yet kept on the dry 

 side. In the fall, all the old soil is shaken from the rhizome, 

 which is planted in a large pot about a seven-inch pot 

 in a rich compost of two-thirds heavy loam and one-third 

 well-rotted cow manure. As soon as the roots are well 

 established, frequent applications of liquid manure are 

 given. They should have strong light, and a temperature 

 of about 55. 



HYDRANGEAS 



516. Botanical classification. Order, Saxifragacese ; 

 genus, Hydrangea (Greek hydor water, and aggeion 

 vessel, alluding to the cup-shaped fruit) ; species, hortensis. 



517. Botanical characters. Ornamental, deciduous 

 shrubs, with simple leaves and small, white, blue or pink 

 flowers in corymbs or panicles, bearing usually sterile 

 flowers, with enlarged showy sepals. 



Habitat. The greenhouse species are native in China 

 and Japan. 



518. Commercial importance. Hydrangeas are im- 

 portant commercially, because of their adaptation to forc- 

 ing for Easter sales. They are also excellent for Memorial 

 Day. They are grown with comparative ease, and are 



