28 SHADE TREES TOR NORTH CAROLINA. 



naturally broadens considerably with age with most species which have 

 deliquescent stems. After the height growth is made, the vitality of the 

 tree is expended in extending the lateral branches, changing the shape of 

 the crown from oval or conical in early youth to broadly oval in middle 

 age and dome-shaped in old age. For this reason in mature trees which 

 are not over high more lateral trimming is usually advisable than trim- 

 ming in the apex of the crown. 



Trees whose boles are unduly long in proportion to the crown should be 

 topped. The topping, accompanied with a small amount of lateral lop- 

 ping, will frequently force the development of shoots on the upper part 

 of the bole from dormant buds. It is advisable to permit the growth of 

 these shoots since they assist in lowering the center of gravity, trees of 

 this kind being top heavy and likely to wind fall. Many of the old oaks 

 and hickories forming parts of groves on public grounds, parks, etc., 

 which were originally forest trees, are of this class, being tall and having 

 the boles too long in proportion to the length of the crown, which, more- 

 over, are very wide-spread (PL V, B). As their comrades have died, they 

 have been left isolated and unprotected from the wind, while their tall 

 stems and large crowns make them liable to windfall, which has still 

 further thinned them. On account of the freer entrance of wind and sun 

 the ground becomes very dry and the tree begins dying in the upper part 

 of the crown. When the soil of such a grove has become decidedly defi- 

 cient in humus, either from the burning of the leaves and grass annually 

 or because the leaves are removed, cultivation for several years and the 

 plowing under of one or two crops of cow peas, or clover will be of great 

 benefit in re-establishing the conditions necessary for healthy growth. 

 In figs. 6, 7, 8 and 9 are illustrated various tools that can be used to ad- 

 vantage in pruning different trees. 



CAEE OF NEWLY PLANTED TEEES. 

 For some weeks newly planted trees should be watered regularly, if 

 the soil is very dry, and subsequently if droughts occur during the sum- 

 mer and autumn of the first season. Usually trees will be well rooted by 

 the end of the first growing season so that watering will seldom be re- 

 quired in subsequent seasons. The earth around the tree should be cul- 

 tivated once or twice a season for several years to assist in the preservation 

 of soil moisture and to add to the permeability of the soil so that all of 

 the rainfall will be absorbed. Mulching with straw or grass cut from 

 lawns will also tend to maintain the soil moisture. Young trees, however, 

 should not be mulched with manure for the first few years at least and, 

 if i In oil has been properly prepared, they will not require it. 



