344 The Principles of Vegetable- Oardening 



if used before the tubers become large and stringy. 

 The tubers should be used when they are from two to 

 three inches in diameter; it is essential that they should 

 have grown quickly and continuously, otherwise they are 

 tough and bitter. Successive sowings 

 may be made and the plants should be 

 thinned to six to ten inches apart in the 

 row. White Vienna is the leading garden 

 variety. Fig. 102. 



Seed required per acre and distances apart for 



Brussels sprouts and cauliflower are essentially as 



for cabbage ; kale is usually allowed to stand 



^. _ , . , . somewhat closer in the rows. For kohlrabi, esti- 



Fig,102. Kohlrabi. . x. ^ • 



mate as tor turnips. 



In 1889 (Annals Hort.) American seedsmen offered 110 varie- 

 ties of cabbage, 29 of kale, 7 of Brussels sprouts, 53 of cauli- 

 flower, 7 of kohlrabi. Goff classifies cabbages as follows (5th An- 

 nual Rept. N. Y. State Exp. Sta. for 1886, p. 185): 

 A. Foliage smooth. 



B. Head flattened. 

 BB. Head round. 



c. Foliage green. 

 CO. Foliage red or purple. 

 BBB. Head egg-shaped. 

 BBBB. Head elliptical. 

 BBBBB. Head conical. 



c. Foliage green. 

 CO. Foliage red. 

 AA. Foliage blistered (Savoys). 

 B. Head round. 

 BB. Head elliptical. 

 BBB. Head conical. 



The cole plants (known to the French under the generic name 

 of cliou) ai'e probably derivatives of one European sea-coast species, 

 Brassica oleracea. It belongs to the Cruciferce or mustard family. 

 The plant is perennial and now grows on the cliffs of southern Eng- 



