How Weeds Spread. 



Ill the present age of extensive and easy commuiiicatiou with all parts 

 of the country, and indeed with the whole world, there are frequent oppor- 

 tunities for seeds of weeds being introduced into previously uninfested dis- 

 tricts. 



There are many ways in which weeds are spread: — 



1. By natural agencies. The wind carries the seeds long distances not 

 only in summer but with drifting soil and over the surface of the snow in 

 winter. Streams distribute them far and wide along their courses. They are 

 also distributed by seed-eating birds and herbivorous animals, througb the 

 stomachs of which the seeds have passed undigested, or by being attached to 

 some part of their bodies by special contrivances, with which nature has 

 provided some seeds for this very purpose, such as hooked and barbed bairs, 

 spines, gummy excretions, etc. 



2. By human agency. The seeds of weeds are frequently introduced 

 as "foul seed" mixed with other seeds, particularly in cheap, improperly 

 cleaned seed; they are also brought on to previously clean farms with ma- 

 nure from towns or are imported in hay used for packing or as fodder. In 

 addition to this, they are often distributed over farms by waggons, harrows, 

 seeders, threshing machines or other agricultural implements. As an offset 

 against the great benefits we derive from railways, it has been found that 

 many bad weeds have been introduced into new localities through their 

 agency, the seeds being either shaken from cars or cleaned out of them at 

 stopping places. 



A fact, however, which should not be forgotten, is that the railway 

 companies do not grow these weed seeds themselves. They are merely the 

 carriers for farmers and would far rather handle grain perfectly free from 

 weed seeds of all kinds than such as contains a possible source of injury to 

 a new district, in the prosperity and progress of which they are interested. 

 It is most important to keep a close watch on all railway banks and station 

 yards so as to detect and destroy any new weeds which may appear, before 

 they spread to the surrounding country. 



Classification of Weeds. 



Weeds, like all otlier plants, may be simply classified according to the 

 length of lime they live, under the three following heads: — Annuals, or 

 one-year plants: Biennials, or two-year plants; and Perennials, or manj'- 

 year plants. In etadirafing weeds, it is of the greatest importance to consider 

 under which of those heads they come, because in most instances the treat- 

 ment is simple and will be upon the general principles of preventing annuals 

 and biennials from seeding, and perennials from forming new leaves, roots 

 and underground stems. 



Annuals. — Are those plants which complete (heir whole growth in a 

 year. As a rule they have small fibrous roots and produce a large quantity 

 of seed. Examples of this class are found in Wild Mustard, Stinkweed, 

 Lamb's-quarters, Wild Buckwheat, Purslane, Eagweed, Wild Oats. There 

 are also some annuals called "^^'inter Annuals," whicli are not only true 

 annuals when the seeds germinate in spring, but are also biennial in habit, 

 that is, their seeds ripened in the summer fall to the ground, germinate and 

 produce a certain growth b(>foro winter sets in and then complete their 

 development the next spring. Of these may be mentioned Shepherd's-purse, 

 Ppppererass, Stinkweed, mentioned above, Wormseed IMustard, Ball Mus- 

 tard, Hare'e-ear Mustard, Canada Flea-bane, and the Blue Bur. 



