Vol. XXXI Washington, D. C., December 15 , 1925 No. 
STUDIES IN WESTERN YELLOW PINE NURSERY 
PRACTICE 1 
By Donald R. Brewster and J. A. Larsen, formerly of the Northern Rocky 
Mountain Forest Experiment Station, Forest Service , United States Department 
of Agriculture 
INTRODUCTION 
In 1912 and 1913, when nursery experiments were started under di¬ 
rection of the then “Priest River ’’ ForestTExperiment Station, at Priest 
River, Idaho, and elsewhere, western yellow pine (Pinus ponderosa) 
was one of the principal species being planted on a large scale in 
the northern Rocky Mountain region and millions of plants were 
being raised each year in the Forest Service nurseries; but com¬ 
paratively little careful study had been made to determine the 
best methods of handling this stock in the nursery to obtain good 
quality at a minimum cost. The experience of the years following 
1909, when the nursery work was first undertaken on a large scale, 
demonstrated beyond question the need of experimentation in order 
to produce a better ana more uniform quality of stock and to avoid 
the delays, uncertainties, and losses due to lack of exact information. 
The investigative work undertaken at this time was limited to 
those phases of the western yellow pine nursery practice most suitable 
for study at a small experimental nursery with limited facilities and 
at a considerable distance from the large nurseries operating on a 
commercial scale. These phases were: (1) Depth of covering seed 
in the seed bed; (2) methods of sowing seed in the seed bed; (3) 
degree of shade to use on the seed bed; (4) amount of water to use on 
the seed bed, with or without cultivation. 
Such phases as the proper amount of seed to sow, the best season 
to sow, the need for fertilizing the soil, development of a good root 
system, and methods and season of transplanting, could at that time 
be studied better at the larger nurseries, either Decause of the large 
scale on which it was necessary to conduct the investigations or 
because the problems were more or less local and could best be 
solved at the nursery where the results were to be applied. 
While the four phases selected for study are to a certain extent 
interrelated with climatic and soil conditions, these conditions at 
the field station in northern Idaho sufficiently resemble those at the 
Savenac Nursery in northwestern Montana to permit putting into 
practice there the results obtained at the Idaho station. The mean 
monthly temperatures for the growing season at Savenac average 
only one or two degrees lower than those at Priest River. Percentage 
of sunshine and wind velocity are probably somewhat greater at 
Savenac, but the same general regional climate prevails at both places. 
1 Received for publication Apr. 14,1925; issued December, 1925. 
Journal of Agricultural Research, Vol. XXXI, No 12 
Washington, D. C. Dec. 15, 1925 
Key No. F-26 
78383—26f-1 
( 1101 ) 
cereal investigations. 
