4 
Colorado Experiment Station. 
ful rainfall. The red raspberry seems to be as much at home in the 
burned over timber lands of the high altitudes of Colorado as in 
Michigan; consequently we may conclude that the soils of Colorado 
are as well adapted as in the eastern states. 
Comparatively few diseases attack the raspberry in the dry climate 
of Colorado. The yield and quality of fruit is equal or superior to 
that of the East. 
Raspberry growing has become one of the important industries 
in several districts of Colorado and it gives promise of proving even 
more valuable in the future because the conditions for the best de¬ 
velopment of fruit may be more readily met on the irrigated lands 
of Colorado than in the uncertain climatic conditions of other parts 
of the country. 
REQUIREMENTS. 
Although the raspberry is one of our fruits that can be raised in 
most any section of the state up to an altitude of ten thousand feet and 
in various kinds of soil, there are certain requirements that, if fol¬ 
lowed, will insure its success. 
Soils .—The native raspberry of the state is found on mountain 
sides where there is a good supply of humus. The cultivated plant 
is grown in soils ranging from a light sandy loam to a heavy clay. 
On investigation it has been found that the earlier fruit is on the 
sandier soils, but the better production comes from those plants grow¬ 
ing in a heavier soil such as a clay loam. The sub-soil is an import¬ 
ant matter as regards drainage. The best subsoil would be that 
of gravel or sand. With less impermeable sub-soils the site requires 
more slope to insure proper drainage. The depth of soil that is 
the best for raspberries is more or less an open question. Perhaps 
six or eight inches of good surface soil is deep enough for a short 
lived plantation. There is no doubt but that a soil two or more feet 
in depth is better for raspberries than a shallower one. The more 
humus that the soil contains at the time of planting the better will be 
the result in growth. 
Climate .—The different climatic conditions which exist in the 
state necessitates two distinct methods of handling raspberries. In 
those sections where the temperature falls to several degrees below 
zero and remains there for any length of time it is necessary to cover 
for winter protection. In those sections where the temperature never falls 
to but around zero it is not necessary to cover either the red or black 
varieties. Then there are other sections where the red varieties have 
to be covered and the black do not need winter protection. As far 
as climate is concerned raspberries will stand the most rigorous 
