350 Elementary Principles of Agriculture 



early planted vegetables that have a short growing 

 season and mature before the season for hot weather 

 arrives. They do not develop crops of good quality in 

 the dry air of summer. They are hardy, however, to 

 light frost and may be planted in the open quite early. 

 Included in this group are garden cress, kohl-rabi, leaf 

 lettuce, radishes, mustard, peas, spinach, and turnips. 



(b) The Late Cool Season Vegetables, like the 

 above, are also frost hardy and favored by cool weather 

 but require a longer time to mature. They are also easily 

 injured by early hot weather. To avoid this possibility, 

 it is usual to grow their seedlings by forcing in the late 

 winter and to have the plants well started and ready to 

 set in the open in early spring. It is a " transplanting 

 group" and includes cabbage, head lettuce, and celery. 

 They are plants grown largely for their foliage. 



(c) Open Season Early Planted Vegetables require 

 a still longer period to mature. They are favored by 

 cool moist weather, particularly in their young stages, 

 but once established will thrive in warm summer tempera- 

 tures. Here belong the potato, beet, carrot, parsnip, 

 salsify, onion, and the perennial vegetables, asparagus 

 and rhubarb. It will be noticed that they are valued 

 because of their fleshy roots, stems or leaf stalks. The 

 vegetables in this group are popular because they have 

 comparatively few enemies, have a long period of edi- 

 bility, and are easy to care for because they endure 

 moderate extremes of heat and cold. 



516. Warm Season Vegetables include crops that 

 are sensitive to even light frost and do not grow well in 

 even cool weather. They are all native of warm climates 

 and require summer temperatures for rapid growth, and 

 the development of large yields and good quality. We 



