Beekeeping in the Clover Region. 7 
usually flowers blooming in the later part of the summer furnish lit- 
tle or no nectar. The chief agent for pollination of this species is 
the honeybee. 
As has been indicated, nectar secretion is not uniform throughout 
the range of this species. The plants thrive best when there are 
good rains in July, August, and September. Winterkilling is less 
noticeable for white clover than for red clover. If there are abun- 
dant rains in May the plants are put into a condition of great vigor, 
and this adds greatly to the probability of a heavy secretion for the 
season. Rains while the plants are in bloom serve to prolong the 
period of blooming and of nectar secretion. White clover is seem- 
Fic. 8.—Map showing average date of last killing frost in spring. From these data 
the beekeeper determines the time to unpack colonies of bees wintered outdoors. 
ingly most valuable as a honey-source in the northern part of its 
range, and this is probably due to the fact that the plants are most 
vigorous and secrete nectar most freely where the temperatures at 
blooming time are relatively low (fig. 2). The species is able to 
reseed itself in central Alaska, where the growing season is exceed- 
ingly short. It is recorded that secretion occurs in the north at 
temperatures too low for bees to fly. It rarely may be counted upon 
as a major honey-source where the average summer temperature ex- 
ceeds 75° F. A more important consideration, however, is that 
secretion is most rapid where there is a considerable daily range of 
temperature, the best results being observed when the night tem- 
perature is below 65° F. and the day temperature above that point. 
While proper climatic conditions are necessary for nectar secretion 
from this species, it is only where soil conditions are favorable for 
