OF WATERING. 121 



More commonly recourse is had to the operation of 

 simple watering, for the purpose of maintaining the 

 earth at a due state of humidity, and to render plants 

 more vigorous than they otherwise would be ; an in- 

 dispensable operation in hot-houses, but of less moment 

 in the open air. It is, indeed, doubtful whether, in the 

 latter case, it is not often more productive of disadvan- 

 tage than of real service to plants. "When plants are 

 watered naturally, the whole air is saturated with hu- 

 midity at the same time as the soil is penetrated by the 

 rain ; and in this case the aqueous particles mingled 

 with the earth are very gradually introduced into the 

 circulating system : for the moisture of the air pre- 

 vents a rapid perspiration. Not so when plants in the 

 open air are artificially watered. This operation is 

 usually performed in hot dry weather, and must neces- 

 sarily be very limited in its effects ; it can have little if 

 any influence upon the atmosphere : then, the parched 

 air robs the leaves rapidly of their moisture, so long as 

 the latter is abundant ; the roots are suddenly and vio- 

 lently excited, and after a short time the exciting 



state of temperature and moisture for the roots. From an experi- 

 ence of some years we do not hesitate to say that mulching the sur- 

 face of the ground over newly-planted trees is not only far better 

 than any after watering — but that — if the layer is thick enough to 

 keep the surface cool — it renders watering wholly unnecessary. In 

 the case of bearing fruit-trees, especially the more delicate kinds, as 

 dwarf pears, apricots, &c, mulching not only precludes the necessity 

 of stirring the soil, by preventing weeds from growing, but it con- 

 duces so much more to the health of the tree, and the size and excel- 

 lence of the fruit than any other practice in horticulture, that the 

 more intelligent growers in the United States now consider it 

 indispensable in this climate, A. J. D. 



6 



