COTTONWOOD IN THE MISSISSIPPI VALLEY. 49 
parison with other poplars is that 1t forms a better shaped stem, freer 
of side branches. Such conclusions are based on a comparatively 
small number of plantations in southern Minnesota, which hardly 
afford sufficient grounds for recommending this tree in preference to 
the better known cottonwood or the Carolina poplar. 
PLANTING SITES. 
Moderately well-drained, permeable bottom lands afford the best 
planting sites. The soil need not be rich or loamy. Very sandy 
land will be suitable if the water table is within from 12 to 15 feet 
of the surface. Even upland sites may sometimes be suitable, pro- 
vided the soil is not too shallow and rainfall is abundant and well 
distributed. Suitable upland sites, however, are apt to be well 
adapted for farming. 
COMMERCIAL PLANTING. 
The cottonwood lumber industry is almost exclusively confined to 
the Mississippi Valley, where maximum returns can be obtained on 
a 35-year rotation, or in the central and southern sections perhaps on 
as short a rotation as 25 to 30 years. Even in the north, where the 
growth of cottonwood is comparatively slow, the better market for 
small sizes will make it possible to produce saw timber in 35 to 40 
years. For the present, however, planting for lumber should proba- 
bly be restricted to the central region. 
The Northeastern and Central States offer another opportunity for 
realizing profitable returns from cottonwood plantations located close 
to pulp mills.. Several pulp-manufacturing companies have already 
started plantations of cottonwood. 
Black cottonwood (Populus trichocarpa Torr and Gr.), which is 
very similar to the cottonwood of the Mississippi Valley, has been 
planted to some extent for pulpwood in western Oregon and Wash- 
ington. The success already attained with this species emphasizes 
the possibilities of our eastern cottonwood in the region. The com- 
mon cottonwood should do well in the Pacific Coast States, where 
the markets for pulpwood and box material should afford a ready 
outlet for the products of plantations. It is not certain, however, 
that Populus deltoides will excel in any respect the native Populus 
trichocarpa. | 7 
PLANTING FOR WINDBREAKS. 
Cottonwood plantations are often warranted where, as in Iowa, 
Minnesota, the Dakotas, Kansas, and Nebraska, timber for lumber, 
posts, and fuel is scarce. Plantations of cottonwood made by the 
ploneers in those States from 30 to 50 years ago, often on dry upland 
sites, have in many instances been sawed up into rough lumber at 
