1326 RiRAL School Leaflet 



always been a question why European j^lants are more i)rone to become 

 weeds than are plants from other countries. The daisy, the orange 

 hawkweed, the Canada thistle, the ma^^weed, the chickweed, and many 

 others have migrated from the Old World. Ragweed and black-eyed 

 susan are examples of the few native plants that are weeds. Perhaps the 

 best explanation so far advanced for the predominance of European plants 

 is that the European weed plants come from a region where the native 

 vegetation is more scanty and open than that of this countr}\ When 

 the farmer clears the soil and opens up the country, planting a part to 

 a crop and leaving other portions fallow, exactly the right conditions 

 are produced for these European plants. 



Many persons are prone to think of the weed as a very aggressive plant, 

 pushing and crowding the more valuable vegetation until like the English 

 sparrow, it becomes dominant. This is only true of a few weeds, primarily 

 those adapted to rich soil and those having the habit of spreading by branch- 

 ing stems below or on the surface of the ground. Most weeds, on the con- 

 trary, are simply squatters on the soil, occupying space not taken by other 

 plants and readily gi\^ng way to the other plants when they become at 

 all aggressive. This will be seen very plainly, if the repopulation of 

 deserted gardens or fields is watched. During the first year after desertion, 

 the field is well populated with a great variety of weeds. During the 

 second 3'ear, the variety of weeds has become noticeably less; clover and 

 grasses have begun to grow. By the third year, a fairly well-developed 

 sod of grass and clover has superseded the varied display of weeds of the 

 first year. Within five years, practically all the original w'eed flora has 

 disappeared. What has happened is that the grasses and the clover, 

 spreading by underground connection, have crowded out the weed flora. 

 In many cases, the weed flora is tolerated only because the soil is too 

 infertile to support the more aggressive economic plants or plants of the 

 native flora. Enriching the soil frequently causes the disappearance of 

 weeds because the economic plants then become m.ore thrifty, and the 

 weeds are crowded out. If more humus is added to the soil, the native 

 vegetation may be stimulated, and the wild plants may replace the 

 weeds. 



Weeds have both their good and their bad sides. Before speaking of 

 the undesirable featiu*es of these plants, it may be well to point out the 

 fact that some of the weeds are among the most beautiful flowering plants 

 there are, and that if it were not for them the summer and autrram land- 

 scape would lack much of its color. A weedy field covered, as it is, with 

 the succession of dandelions, buttercups, daisies, goldenrods, and asters, 

 forms one of the most beautiful pieces of planting that the writer 

 knows. 



