XVI WEEDS. 



plants grow, that he may know how to direct his efforts to subdue them. 

 A perennial weed, like the Canada Thistle or Couch Grass, is, during the 

 early stage of its existence, easily destroyed ; but later in the season it 

 makes strong underground stems, or roots, as. they are commonly but in- 

 correctly called, which have great tenacity of life, and which have within 

 them an accumulation of nourishment which enables them to throw up 

 several successive crops of herbage ; plowing such weeds generally ag- 

 gravates the trouble, for, unless every fragment be removed from the 

 ground, a thing very difficult to accomplish, each piece that is left makes 

 a separate plant. In the case of weeds of this description, the necessity 

 of early eradicating them is apparent, for if once well established, and 

 an underground provision depot formed, the farmer and the plant are 

 placed in the condition of beseiging and beseiged forces as long as the 

 provisions hold out the latter can maintain its ground. It becomes a 

 question of endurance, for the underground supply must be eventually 

 exhausted in the attempt to produce new stems and leaves, and if the 

 farmer, by persistently cutting these away, prevents any new accession 

 to the stock of provision, the enemy must at length succumb. Often re- 

 peated cuttings will at length exhaust the underground portion of its vi- 

 tality. In some cases salt has been used with success, especially upon 

 Thistles, applied immediately after mowing. The farmer will do well to 

 keep in mind two rules. Do not let weeds flower, and do not let them 

 breathe, for the leaves may be considered the lungs of the plant, and 

 without the aid of these it cannot long maintain itself. 



