626 HORTICULTURE, FORESTRY, FLORICULTURE 



have been removed. With roses, the stems should be shortened one- 

 third to one-half. There is endless discussion concerning this, how- 

 ever, due in part to different conditions. The gardeners rule is to 

 cut back the weak growing varieties severely, and the stronger ones 

 less. In general, heavy pruning among roses encourages more vig- 

 orous growth with fewer and finer flowers, while the opposite treat- 

 ment results in more flowers which are, of course, smaller and 

 shorter stemmed. Vigorous growing vines, like the native Virginia 

 creeper and the Arizona grape may have practically all the secondary 

 growth cut away during the dormant season, as this dies of itself 

 sooner or later, thus forming lodging for dust, insects, and sparrow 

 nests. (Ariz. E. S. Cir. 81.) 



The Protection of Shade Trees. Protectors are of three kinds. 

 The young tree needs a support to hold its trunk erect and its roots 

 in place against the soil ; it also needs a guard to shield it from the 

 bites of horses and other injuries to its stem ; and it often needs a 

 grill to prevent the trampling of the earth about its base and the con- 

 sequent injury to its roots. 



The support is usually a straight pole or joint ten to twenty 

 feet long made of chestnut, spruce, oak or other wood set firmly in 

 the ground next to the tree either on the south side, where it shields 

 the stem from the sun, or in line with the row of trees, where it is 

 least conspicuous. The tree is attached to its support in several 

 places by means of iron, leather or cloth bands padded with cushions 

 of wool, rushes, or other soft material to prevent abrasion. The sup- 

 port is removed at the end of the third or fourth year after planting, 

 or when the tree is fully able to support itself. 



The most common tree guard is an elongated box made of nar- 

 row boards which encloses the stem of the tree up to a distance of 

 five feet or more from the ground. The box guard is easily made 

 and very efficient, but clumsy and unsightly and affords an excellent 

 retreat for insects. Wire netting is a cheap and excellent protector 

 for trees and is now extensively used. In the case of young trees, 

 it may be passed around the stem and nailed to the support ; while on 

 older trees it is usually attached to wire nails driven into the trunk. 

 The best guards are made of iron. All guards of whatever kind 

 should be fastened securely to the tree in such a way that no injury 

 will result from rubbing; and, as the trees grow larger, care should 

 be taken to loosen and enlarge the guards as the trees require. 

 (Cornell E. S. B. 205.) 



GENERAL CULTURAL SUGGESTIONS. 



Germination. The germination of seeds depends upon a proper 

 degree of heat, moisture, and air (oxygen). All three of these con- 

 ditions must be present in normal proportions with each of the others 

 in order to insure the best germination of the seed. Some seeds 

 germinate best under a maximum degree of heat (80 to 90 F.) 

 while others do best at a low temperature (40 to 60 F.) . For most 

 seeds, however, a soil temperature a few degrees higher than that of 

 the surrounding air is desirable. A soil temperature of from 65 to 

 70 F. for an air temperature of 60 F. will prove very satisfactory 



