18 SHADE TREES EOR NORTH CAROLINA. 



growth. The more unfavorable the conditions and the poorer the soil 

 the greater care should be taken in its preparation. For park and estate 

 planting, where the roots of the tree have ample room for spreading, a 

 hole 3 feet square and 2 feet deep is ample for small trees. If the soil is 

 naturally of only fair quality, the top layer should be placed in a separate 

 pile from the raw subsoil, and should be well mixed with leaf mold, if 

 such is available, and placed in the bottom of the hole as a bed on which 

 to place the tree. A portion of the subsoil should also be mixed with 

 leaf mold, or, if this is not available, well decomposed manure, or litter, 

 can be substituted, and used for filling the hole about the newly planted 

 tree. A tree planted in such a manner will make rapid and sustained 

 growth, and while under the best conditions such care and expense are not 

 necessary, the excellent health of the specimen will usually compensate 

 for the additional cost. As the conditions for tree growth become less 

 propitious, as along the paved streets of towns where the soil moisture is 

 frequently insufficient, the greatest care must be exercised if healthy, 

 vigorous specimens are to be obtained. On paved streets, where it is de- 

 sired to secure ultimately large specimens, the planting hole can well be 

 made even larger than 3 by 3 feet, either by increasing the width on all 

 sides or extending one side so as to have the greatest length paralleling 

 the curbing. The earth in all such cases, unless naturally very fertile, 

 should have well decayed leaf mold or litter added to it in the proportion 

 of about one-third. 



The most essential requirement for the healthy growth of trees, so far 

 as the roots are concerned, is a uniform, though not excessive supply of 

 soil moisture. Some soils, on account of their situation or character, 

 are naturally more subject to drying than others. The addition of the 

 well rotted leaf mold to such soils not only adds a store of easily available 

 plant food, but greatly increases their water-carrying capacity, enabling 

 them to store large quantities of rain water for the future needs of the 

 tree. At the same time, soils which are wet are apt to be sour, especially 

 when heavy clays, and this condition is fully as unfavorable for healthy 

 growth as when there is a deficiency in the moisture supply. Such sour 

 soils are usually compact clays and it is often difficult to properly under- 

 drain them. Slow and unhealthy growth and small yellowish foliage 

 are an excellent indication of a soil's being sour, if it is wet. The addi- 

 tion of a small amount of lime to the soil is a temporary corrective, 

 although drainage is necessary for permanency. Pin oak, willow oak, red 

 maple, Mack gum and sweet gum are more suitable, for sour soils than 

 other Bpecies. White oak, red oak, black oak, sugar maple, linden, yellow 

 poplar and cucumber are intolerant of such conditions. The addition of 



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