HORTICULTURAL JOURNAL. 249 



nevertheless, a fact that soils, even of a dry nature, will support a more lux- 

 uriant vegetation after being undermined with drains, than they did before. 

 The reason is simply this : All soils have their respective absorbing proper- 

 ties, and if the surplus which is not retained by absorption, is not carried 

 off by drains, it becomes injurious. Air is admitted, the soil is rendered 

 more porous, water percolates freely into it, the air holds moisture in sus- 

 pension, and when the surface supply fails, this suspended moisture is again 

 brought up by capillary attraction, a principle in cultivation which is not 

 generally known. 



But by far the best preventive of the evil effects of severe drought, is deep 

 cultivation. Loosen the soil, no matter how deep, so that the best soil is 

 kept on the surface. Trenching is undoubtedly the most thorough process 

 of deepening soil. The advantages derived from it are various. The ab- 

 sorbing capabilities of the earth are increased, and a large supply of mois- 

 ture is thus retained. The roots of plants can extend into a medium where 

 they are exempt from the extremes of drought and heat, and obtain a more 

 regular supply of nourishment, being neither so likely to suffer in wet, or 

 burned up in dry weather ; as in the former case the surplus passes freely 

 down, and in the latter is drawn up by capillary attraction, more especially 

 where a judicious system of surface stirring is persevere J in, preventing 

 rapid surface evaporation. 



In addition to the supply of moisture thus secured, trenching, when pro- 

 perly performed, transposes and disintegrates the soil. The surface that has 

 been exhausted by continual cropping, is replaced by a portion of sub-soil, 

 enriched with the nutritive matters that have naturally sunk and been 

 washed down with rains from the surface, and carried beyond the reach of 

 roots ; the manures applied are more freely incorporated with the soil, and 

 their action becomes more regular and uniform, and more directly available 

 for the purposes of vegetable growth. 



Artificial waterings are often misapplied ; for instance, it is no uncommon 

 occurrence to see a small basin formed around the stem of a large tree, into 

 vrhich a few gallons of water are poured daily. This is all but useless, since 

 the absorbing and feeding points of roots form a circle at a considerable 

 distance from the stem, consquently this water cannot reach them. Newly 

 planted trees are also frequently killed through kindness in this respect. A 

 tree with mutilated roots and scanty growth of leaves, requires very little 

 water. Mulching over the roots with a covering of tan bark, manure, &c, 

 is a more likely expedient than a direct application of water, which cools 

 the soil and retards growth. 



