EEFORESTATION ON THE NATIONAL FORESTS. ^9 
It has the disadvantage that the seed often fail to germinate until the 
following year, or until about the beginning of the dry season, when 
the seedlings have little chance of surviving. 
SUMMER SOWING. 
Summer sowing is very generally inadvisable, except possibly in 
those regions, such as Arizona and New Mexico, which are character- 
ized by a rainy period beginning in July. Even in these regions sum- 
mer-sown seed have only a short growing period after germination 
and are very likely to be harmed by early frost. 
SEASON FOR SOWING IN DIFIERENT REGIONS. 
While sowing has not proved satisfactory in general at any par- 
ticular season, experience gained so far in Forest Service operations 
indicates that the best results may be expected from early spring sow- 
ing in Montana, Wyoming, and Colorado east of the Continental 
Divide, the Black Hills of South Dakota, and possibly the Lake 
States. Similarly, the indications point to fall as the best period in 
Colorado, Wyoming, and Montana west of the Continental Divide, 
Idaho, Arizona, New Mexico, Utah, California, Washington, and 
Oregon. 
FIELD ORGANIZATION. 
The sowing of a certain area or the planting of an assignment of 
trees involves the problem of doing a definite amount of work on se- 
lected sites while certain conditions prevail. In the fall, planting 
must be done after the soil has become sufficiently moist and before 
winter sets in ; in spring, shortly after the snow goes off and before 
the summer begins. It is important, therefore, to learn beforehand 
just what field organization will be necessary to complete the work 
in the time that is available. 
Crew. 
The number of men desirable will depend largely upon the scope of 
the operations, the length of the season, the method followed (whether 
it be a slow or rapid one) , the topography and cover of the site, and 
the nature of the supervision possible. Because of the limited length 
of the planting season, the possible interruptions through short spells 
of bad weather, and the deterioration of the planting stock when 
heeled in at the planting site for any considerable period, the crew 
should be as large as is consistent with efficiency and proper supervi- 
sion. Crews generally consist of from 6 to 24 men each, although 
much larger ones may be employed. In very rough, mountainous 
country or on areas coA^ered with much brush or down timber, where 
