PLANTING AND SEEDING SEASONS : Page 17

In the extreme northernmost area, except that of Camden, Maine,the fall planting season does not open early enough, nor does the springseason extend long enough to offset the long winter period of frozenground, which may extend to five months in the Northern Zone.Thus the total number of working planting days in the Northern Zonemay be only 70 or 80 in an average year of not unusual severity ofwinter, while in the great central portion of the country each of thetwo seasons may be as much as 50 days long, giving a combined plant-ing season of about 100 working days. In the Southern Zone, wherethere is no interruption during the winter, the season may be from 115to 150 or even 160 days long, except that the beginning of growth in thespring curtails the season at that end when the Tropical Zone is ap-proached. It should be noted that the farther south one goes the moreabruptly the spring growing season opens and the harder it becomes toprolong the planting season by any of the expedients mentioned above.The growing seasons of the southern sections of the United States openrapidly and there is greater danger in the operation of transplantingafter leaf growth has started than in the cooler northerly sections of thecountry. It is also inadvisable to import cold storage plants intosuch southerly sections much after the time when local stock is infull leaf.