succeeds best, making the windbreak effective only to the full height of the 

 spreading trees. Figure 5. 



When but one row is used, planting should be quite close. Slender trees 

 should not exceed four feet and spreading trees six feet apart in the row. Single 

 rows of spreading trees will occupy more space if not pruned or trimmed up 

 than two rows of slender ones. The two rows of slender trees, however, are 

 more effective than the single row of the spreading trees. Figure 6 shows 

 typical single-row windbreaks of black locust and of Lombardy poplar. 



The second and additional rows of trees render windbreaks much more 

 effective. For a tall and comparatively permanent shelter, a single row of 

 spreading trees with two rows of tall ongs to the leeward are very effective. 



A very desirable large windbreak for this district can be established by 

 planting two rows of Russian oleaster, Elaeagnus angustifolia, one or two rows 

 of black locust, and two rows of Lombardy poplar. To place one or two rows 



Figure 5. (a) Black locust and Lombardy poplar planted alternately in the row. The locusts are 



one year younger than the poplars. 

 (b) Carolina poplar, showing loss of leaves in midsummer. 



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