THE FOREST NURSERY 237 



develop a rambling root system with few fibrous roots when the 

 soil is poor and overlight. As a result, they are difficult to lift 

 and set in the plantation and the loss is excessive. The root sys- 

 tem is small and imperfectly developed and the plants are difficult 

 to lift without injury when the soil is heavy. 



It is a mistaken belief that, when planting is to be done on a 

 poor site with inferior soil, the stock should be grown on a similar 

 soil. The stock for planting on all sites should be as well devel- 

 oped and vigorous as possible. It should be grown on the most 

 favorable soil and under the best conditions. 



9. SLOPE, ASPECT, AND SURROUNDINGS 



A perfectly level site is usually undesirable, particularly if the 

 soil is somewhat heavy. A level site is preferable on light, sandy 

 soil. A gentle slope, just sufficient to permit perfect drainage, is 

 best for the average site. If the slope is more than 5 degrees, 

 erosion is likely to occur and terracing is necessary in forming the 

 seedbeds. The location of the nursery with reference to aspect 

 depends chiefly upon latitude and altitude. Eastern and southern 

 aspects are best for most species in cold regions of adequate rain- 

 fall. In most localities in temperate United States, eastern and 

 southeastern aspects should be avoided because of the greater 

 frost danger, and southern and southwestern aspects because of 

 overdryness of the soil during periods of drought. 



Where provision is made for irrigation, southern aspects in 

 northern latitudes and at high elevations are best because of their 

 greater warmth. For most localities in the United States, how- 

 ever, a northern or western aspect is best because the vegetation 

 starts later in the spring and is not so much injured by frost, and 

 the loss of water through evaporation from the surface soil is not 

 so rapid. 



Nurseries should not, as a rule, be established in narrow 

 valleys or at the depths of deep canyons because the lack of 

 direct sunlight for a large part of the day seriously checks 

 growth. Such sites are also subjected to frost damage because 

 the colder air seeks the lower elevations in hilly and mountainous 

 regions. 



The nursery should not be fully exposed to the free sweep of 

 the wind. It should be protected by a high forest or a well- 



