24 



GARDENING FOE THE SOUTH. 



Humus has the property of producing a constant sup- 

 ply of carbonic acid by slow combination with oxygen. 

 It aids greatly in keeping a soil in an open state, so as to 

 allow water and air to pass freely through it, and by vir- 

 tue of its porosity it condenses and retains gaseous mat- 

 ter within, and it absorbs saline substances. Though such 

 a soil freely parts with a superabundance of water, yet in 

 dry weather it imbibes from the atmosphere large sup- 

 plies of moisture. Schiibler found that 100 pounds of 

 dry humus would hold 190 pounds of water without los- 

 ing a drop. In dry weather 1,000 grains of it spread up- 

 on a surface of fifty inches absorbed from the atmosphere 

 in three days 120 grains of moisture. Of silicious sand 

 the same amount absorbed nothing ; sandy clay, 28 grains ; 

 loamy clay, 35 ; stiff clay, 35 ; garden mould, 52. Hence 

 the best defence we have against drought is an abundant 

 supply of decayed organic matter in a loamy soil. Clay, 

 sand, humus, and lime, will neither of them, if pure, sus- 

 tain a healthy vegetation ; but properly mixed, constitute 

 the main ingredients of the richest soils in the world. As 

 good loam contains sufficient lime, therefore loam, peat, 

 and sand, in varying proportions, are constantly employ- 

 ed by gardeners as the essentials for proper development 

 of the plants they wish to grow therein. 



Where true peat cannot be obtained, leaf-mould from 

 the woods, black muck from the swamps, well decomposed 

 and sweetened by exjDosure, or thoroughly rotted turf 

 mixed with powdered charcoal, are the best substitutes.* 



The depth of a soil is quite as important as its texture. 

 If not naturally deep, it must be made so by trenching. 

 Deep soils retain a constant supply of moisture in dry 

 weather, so that the plants do not suffer ; they do not be- 

 come too wet in rainy seasons, as the earth drinks in and 

 retains the rain below the surface ; hence they are not so 



* (Rural Cyclopedia, Dr. Lindley.) 



