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Spring and autumn are the best seasons for pruning. The cold 
of winter interferes with the execution of the work and also 
freezes the cambium and prevents the healing of the wound, 
which should begin soon after the branch is removed. In sum- 
mer, the leaves are in the way and the removal of branches 
endangers the life of an equal number of roots, which die for 
lack of food. Light thinning of the top may be done in summer 
without inju 
The et weather of autumn makes this season an attractive 
one for the work of pruning. During the autumn days, also, the 
roots continue active because the soil remains warm and consid- 
erable nutriment is sent up to the buds for the next year’s growth. 
fthe pruning is done just after the leaves fall, the remaining 
buds get the full benefit of all this nutriment. Advantage should 
be taken of this fact when weak trees are pruned in order to in- 
vigorate them. The disadvantage of fall pruning is the checking 
and possible decay of the exposed wood caused by the severe 
and changing weather of winter, which follows too soon to allow 
the inactive cambium to close the wound. Large wounds are 
never closed in one season, but most of the ordinary cuts made in 
spring pruning are covered over entirely before the winter sets in. 
The best time for general pruning in New York State is in the 
spring before growth begins, or from the middle of February to 
the middle of April. Sap-running trees are best pruned from the 
middle of May to the middle of June. In case fall pruning is 
preferred, trees that run sap should be finished before the middle 
of October and other trees after this time. Injured or dead limbs 
should be removed when observed. The latter are best seen 
before the leaves fall. Dead branches are unsightly and danger- 
ous to passers-by and to children playing beneath them, while 
they also endanger the life of the tree by carrying decay into its 
trunk, A hollow trunk often has its beginning in a neglected 
dead branch. Dead branches also absorb sap and afford breeding 
places for injurious insects and fungi. 
The removal of large branches is always attended with a certain 
amount of risk and this risk is largely increased when more than 
one or two are removed during the same season; but if the 
