WEATHER IN CRANBERRY CULTURE 55 



WEATHER SEQUENCE AND FROST OCCURRENCE 



Cranberry frosts have generally come later in the spring and earlier in the fall 

 in Massachusetts and New Jersey after the months January to April as a unit 

 have been colder than normal in the Great Lakes region, as shown by table 8. 

 All the harmful spring frosts later than June 9, of which there have been 13 in 

 Massachusetts and 5 in New Jersey, all 12 of the August frosts in Massachusetts 

 except the 2 in 1925, 9 of the 12 fall frosts in New Jersey before September 20, 

 all 8 of the frostless seasons of less than 88 days in Massachusetts, and all 4 of 

 the frostless seasons of less than 109 days in New Jersey have followed such cold. 



It may be worth noting that all the more harmful frosts in Wisconsin cranberry 

 history (p. 58), except those of June 1903, came after February, March, and April, 

 as a unit, had been colder than normal at LaCrosse, Wisconsin; and that all three 

 of the summer frost-free periods of less than 30 days in that State came after the 

 months January to April, inclusive, as a unit, had been very abnormally cold. 



It should be taken as an omen of unusual frosts in southern New England if the 

 mean annual temperature of either northern^^ or southern New England has been 

 distinctly below normal the previous calendar year. Frosts in June and in the 

 fall before the middle of September In southern New England have usually come 

 after March and April as a unit have been colder than normal in northern New 

 England. 



Cranberry frosts have not only usually occurred later in the spring and earlier 

 in the fall but also tended to come oftener and be more severe when the 

 above correlations favored their occurrence. Material like this may perhaps be used 

 presently as a basis for better management of bog flooding. The winter water, 

 or late April reflow, should probably be held well into May on bogs with water 

 supplies for frost flooding when frost is most likely to occur in June. This will 

 delay blossoming and so prevent the development of a situation like that of June, 

 1918, when the bogs were generally nearly in full bloom and so could not be flooded 

 safely when severe frost came. On the other hand, when June frosts are not likely 

 and the growing season promises to be long, the winter water should be held late 

 on bogs that cannot be reflowed. for this will largely insure the crop from frost injury. 



All August frosts in Massachusetts cranberry history, except that of August 30, 

 1934, have followed a June-July unit colder than normal in northern New Eng- 

 land; and all the widely destructive August frosts in Wisconsin, except that of 

 1893, have come after July has been definitely cool in that state. Soil temperature 

 may be involved here. 



^^Northern New England; Maine, New Hampshire, and Vermont; Southern New England: 

 Massachusetts, Rhode Island, and Connecticut (as defined in Climatological Data). The mean 

 annual temperatures are given in the Climatological Data Annual published yearly by the office 

 of the U. S. Weather Bureau at Boston. 



