Immense areas are planted in truck crops in various parts of the South because of favorable climatic conditions. The earlier season makes it possible to produce vegetables and place them on northern markets before local supplies arrive in large quantities. Yields southward are not usually larger, although it may be possible to remove more crops from the same area in a season. Long and warm seasons are also favorable to soil improvement. In many parts of the South it is easily possible to harvest two or even three cash crops in ample time to start a soil improvement crop. Cowpeas can often be worked into the rotation at midsummer, while such a course would be impossible in northern sections. These climatic advantages have made the South famous for its extensive trucking enterprises.
The cooler sections of the North also have their advantages. Insect and fungous pests are less troublesome than in the South. There is not so much leaching of soluble plant foods from the soil during the winter and the cooler weather is favorable to the culture of certain crops, as potato, cabbage, celery, pea and onion.
Large bodies of water often make climatic conditions favorable for vegetable gardening. The success of cauliflower on Long Island is largely attributable to cool breezes from the sea. The winter season at Norfolk is shortened and made milder by the Gulf Stream. In lake districts there is much less damage from frosts in late spring and early fall than in similar latitudes where water influence is lacking. A Canadian tomato grower who plants near Lake Ontario has ripe tomatoes as soon as expert growers at high altitudes in Pennsylvania.