Our harsh, capricious climate north of the latitudes of Philadelphia, Cincinnati, and St. Louis—so much severer than that of corresponding latitudes in Europe—is unfavorable, or at least very trying, to all the more delicate and luscious Fruits, berries excepted. Except on our Pacific coast, of which the Winter temperature is at least ten degrees milder than that of the Atlantic, the finer Peaches and Grapes are grown with difficulty north of the fortieth degree of latitude, save in a few specially favored localities, whereof the southern shore of Lake Erie is most noted, though part of that of Lake Ontario and of the west coast of Lake Michigan are likewise well adapted to the Peach.
It is not the mere fact that the mercury in Fahrenheit’s thermometer sometimes ranges below zero, and the earth is deeply frozen, but the suddenness wherewith such rigor succeeds and is succeeded by a temperature above the freezing point, that proves so inhospitable to the most valued Tree-Fruits. And, as the dense forests which formerly clothed the Alleghenies and the Atlantic slope, are year by year swept away, the severity of our “cold snaps,” and the celerity with which they appear and disappear, are constantly aggravated. A change of 60°, or from 50° above to 10° below zero, between morning and the following midnight, soon followed by an equally rapid return to an average November temperature, often proves fatal even to hardy forest-trees. I have had the Red Cedar in my woods killed by scores during an open, capricious Winter; and my observation indicates the warmest spots in a forest as those where trees are most likely to be thus destroyed.