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in much the manner of the fully developed tree. But despite this 
more luxurious growth they do not make sufficient shade to protect 
the soil beneath them, and unless cultivation is thorough there will 
soon be a compact sod of the strong-growing prairie grasses among 
the trees that will take from them much of the soil moisture and thus 
materially check their growth. The same thing is true of all the more 
valuable broad-leafed trees. The Black Cherry, although a dense- 
shading species while young, does not grow rapidly enough to be used 
as a nurse tree, and is too expensive. Catalpa, a good shade-making 
tree in midsummer, is about the last species to leaf out in the spring 
and the first to drop its foliage in autumn; moreover, its branches are 
So persistent that it needs the help of a denser-shading variety to check 
lateral growth at the earliest possible moment. 
The other economic species that are easily obtainable in the West— 
the Oaks, Chestnut, Walnuts, Hickories, Tulip, and Locusts—will all 
profit by the protection or formative influence of a good nurse during 
the first ten years after planting. 
The conifers that have been planted with dense-shading nurse trees 
in the West have succeeded well, and have stood more shade than one 
would suppose. At the Brookings (S. Dak.) Station White Spruce and 
Colorado Blue Spruce are completely overtopped by the nurse trees 
which surround them and show no distress, while Scotch Pine and 
European Larch fully equal in height the Boxelder and Maples with 
which they were planted ten years ago. 
From the standpoint of the farmer, dense-shading nurse trees are 
useful because they reduce the period of cultivation and the consequent 
cost of the plantation, and greatly increase its effectiveness as a wind- 
break. Toaccomplish this purpose, the nurse must be a rapid growing 
or spreading species that shall completely shade the ground, when 
planted 4 by 4 feet, at the close of the second or third season. 
Using such a tree, it will be found that the second year cultivation 
will be somewhat interrupted by the growing lateral branches, while 
during the third year not more than half the cultivation required the 
first season will be necessary, if any, and thereafter there will be no 
need of cultivation whatever, provided the density of the crowns is 
preserved. Contrasting this with the care of a grove in which light- 
foliaged species, such as Cottonwood or Aspen, form the majority of 
the trees set, or one in which the trees are planted at greater dis- 
tances, it will be seen that continued plowing is necessary to keep down 
the weeds and grass. 
It may seem unnecessary to keep the soil free of weeds and grass, but 
it Should be remembered that the most important factor in all cultural 
operations in the drier parts of the country is the saving of soil moisture. 
With a limited rainfall and excessive evaporation, the farmer is com- 
pelled to save to his plants, by every device ih his power, such moisture 
