12 



FARMERS BULLETIN 788. 



wood. For this purpose green ash or red oak is recommended. On 

 the drier situations the main planting must be done with some of 

 the more drought-resistant species which do not attain such great 

 height. Green ash or locust for the main belt and osage orange for 

 the hedge can not be excelled. 



In the western part of this region more attention may have to be 

 given to westerly winds, and the direction of the rows changed. In 

 eastern Colorado, for instance, the windbreak must be planted so as 

 to afford protection from the spring winds from the west, which are 

 often very damaging. 



FIG. 8. When mature, eottonwooil must be underplanted if the belt is to retain its 



efficiency. 



On the northern prairies (western Minnesota and the Dakotas) 

 southerly summer winds are not so much felt as the westerlies. Here 

 windbreaks should be mainly north-south ones, although some pro- 

 tection on both the north and the south sides of the farm may be 

 needed. Scotch and Norway pines, Colorado blue spruce, and Black 

 Hills spruce are recommended where moisture is sufficient for them, 

 because they give so much better winter protection than the hard- 

 woods. On drier situations western yellow pine may be substituted 

 for the Norway. 



In the Lake States practically all damaging winds are from the 

 west, although the orchard may need just as much protection from 



