344 VEGETABLE GARDENING 



land at the same time, one of these crops being removed 

 before the other crop needs the entire space. For example, 

 cabbage may be interplanted with lettuce, or radishes may 

 be planted between rows of beets, carrots, or parsnips. 



The market gardener may start a crop on his land in 

 early spring for early summer harvest and at that time 

 start another crop to be harvested in the fall. In the 

 Southern States, three crops are frequently grown in suc- 

 cession. In the North, however, but two crops can be 

 grown in this way. Market gardeners frequently plant 

 beets, cabbages, and onions in early spring, harvesting 

 them in July. The land is then planted to celery, which is 

 harvested in the fall. Rutabagas, turnips, spinach, and 

 late cabbage are also commonly grown as a second crop. 

 This system of cropping is called succession cropping. 



Rotation. For the vegetable garden, crop rotation is 

 important. Different plants differ in their food require- 

 ments. Some crops require a liberal supply of nitrogen, 

 while others demand more potassium. Crops that are 

 grown annually upon the same land are most subject to 

 serious injury from diseases and insect pests. All of these 

 points should be carefully considered, not only that the 

 crops may mature at the most desirable time and with the 

 least expenditure of labor, but also that all portions of 

 the land may be used to the best advantage. 



Disease Prevention. No vegetable crop is entirely 

 immune from diseases. Of the preventive measures, spray- 

 ing is of first importance. The spores alighting on the 

 surface of the fruit or foliage may be killed by spray mix- 

 tures during their germination. Rotation is also an im- 

 portant means of preventing disease, as many of the 

 spores live over in the soil from year to year. New land is, 



