88 MONTANA EXPERIMENT STATION 



rush through underneath. Nor will a grove of low-growing shrubs 

 serve all the purposes of a windbreak. It must be a combination of 

 the two. The width should be from fifty to one hundred feet, or 

 even wider, depending upon the force of the winds. 



In most sections of Montana east of the Divide, the troublesome 

 winds are largely from the north and west. This means that the 

 home grounds must be protected at least on these two sides. The 

 windbreak should be far enough from the buildings so the snow 

 which collects inside will not be annoying. With a properly con- 

 structed break one hundred feet is probably a safe distance. The 

 planting should be so arranged that the snow will collect among the 

 trees as much as is possible. To encourage this the smaller trees and 

 shrubs should be planted to the windward and the others arranged 

 in order of height, with the taller ones inside. 



In figure 2 the windbreak is made up of one row of Russian 

 olive on the north and west, one row of box elder next, then two rows 

 of box elder and green ash mixed, and on the inside two rows of 

 poplar or cottonwood. The drifting snows should pile up within 

 this grove and greatly increase the moisture supply. 



In the makeup of the windbreak, the most promising trees are 

 the Canadian poplar, native cottonwood, box elder, golden "Russian 

 willow, green ash, white elm and Russian olive. The Canadian 

 poplar (Populus balsamifera) is one of the hardiest of the poplars. 

 It is a rapid grower and lasts well. The common narrow-leaved 

 cottonwood found growing along the streams in the eastern part of 

 the State may be used for the windbreak or the yard. It is probably 

 not so rapid a grower as the Canadian poplar and does not last as 

 well. It should not be used when the poplar can be secured. The 

 box elder is also a native of the State and will thrive under most 

 conditions. It is a tree of rather straggling habit, grows rapidly and 

 serves well in the windbreak as a tree of intermediate growth. 



The golden Russian willow will succeed on good soil with a 

 little more than the average rainfall. It makes a rapid, dense growth, 

 may be trimmed low, and where the conditions are favorable it is an 

 excellent tree for either the outside or the second row in the wind- 

 break. The green ash is found growing along the streams of eastern 

 Montana. With good care it may be induced to grow on the dry 

 farm, especially when planted in groves. It is not so rapid a grower 



