i6 
COLORADO EXPERIMENT STATION 
from winds is desired, it is usually necessary to plant several rows 
of different species, so arranged that the low, dense-growing kinds 
will fill in the places between the taller ones. 
For the taller-growing tree in this region the common cotton¬ 
wood may be used, setting them about eight feet apart for the outer or 
north and west rows. A second row of some denser-growing kind 
should be planted about eight feet from the first and as close as four 
feet in the row. For this purpose box elder is a suitable tree, except 
in dry situations, in which case the green ash is recommended. The 
trees in the third row may be planted the same as in the second row, 
using a more compact-growing kind. The Russian golden willow is 
recommended for this purpose as a rapid grower. The Russian wild 
olive is a more compact tree of lower growth and is particularly 
desirable. White or American elm is also a suitable tree for the inner 
rows in many places, especially where a fair amount of moisture can 
be depended on. 
In cases where the wind is exceptionally strong, it may be found 
necessary to plant a belt four or five rods wide, in order to secure 
complete protection. The outer two rows may consist of Russian olive, 
the third and fourth rows of black locust, the fifth and sixth rows of 
box elder or ash, the seventh and eighth rows of American elm, and 
the inner two or three rows of cottonwood or Carolina poplar, the 
rows being about eight feet apart. The golden Russian willow may be 
used in place of the elm, and honey locust may take the place of the 
black locust. 
The ground should be prepared as carefully as for a crop of grain 
or sugar beets. Where the rows are to stand, the soil should be 
furrowed out each way by making a back furrow between each two 
rows. When harrowed, the land will slope each way toward the trees 
thus tending to collect drifting snow where it is most needed. 
The same care in planting should be taken that would be given 
in setting an orchard. Seedling trees, two years old, are better in 
most cases than large ones, as they will bear transplanting more 
readily, are easily handled, and the cost is much less than with the 
larger sizes. Trim off all broken and bruised roots with a sharp knife 
and cut back the top to correspond. Set the trees an inch or^two 
deeper than in the nursery, and firm the soil about the roots. 
As soon as planted, irrigate if water is available. If not, give 
a shallow cultivation to check surface evaporation from the soil. 
Cultivation should be continued during the growing season, espe¬ 
cially after each rainfall. This is particularly necessary on the 
plains or where water for irrigation can not be supplied. Such cul* 
tivation is calculated to keep a thin layer of fine, dry soil on the sur-' 
face, which acts as a mulch to conserve moisture. Such care should 
be continued during the first three to five years, or until the trees 
shade the ground between the rows. A mulch of old straw at this 
time may be placed between the rows, and will assist the trees in keep¬ 
ing down the grass and weeds. 
