GENERAL HINTS FOR THE ERADICATION OF 

 POISONOUS PLANTS 



Wherever plants known to be poisonous are found, some effort should 

 be made to destroy them, or prevent at least their multiplication. In 

 most cases they may be simply dealt with as weeds, as annuals, biennials, 

 or perennials. 



ANNUALS: Annuals, which produce their flowers and seeds in one 

 season, have no other means of propagation than seeds. Therefore any 

 method, best chosen by the individual farmer, which will prevent the 

 production of seeds will exterminate the plant. As the purple cockle, 

 cursed crowfoot and Indian tobacco are all annuals, much loss may be 

 avoided by mere hand-pulling or cutting when these plants are in flower. 



BIENNIALS: Biennials, which bloom and ripen their seeds the second 

 year, may be treated as annuals as far as the production of seed is con- 

 cerned. They will eventually succumb to continued close cutting or to 

 the use of the hoe or spud. Thorough cultivation and drainage where 

 necessary is the better method on large and badly infested areas. 



PERENNIALS: Perennials are propagated both by seeds and by under- 

 ground rootstocks, bulbs, or tubers. The prevention of seed production 

 is quite as important as the destruction of the underground portion of the 

 plant, in many cases, more so, as the numerous light seeds borne to fresh 

 soil will in time produce many more new plants than is possible by the 

 division of the rootstocks. But in other cases, as for instance the water 

 hemlocks, the portion in the soil is the most deadly, and any small piece 

 uprooted and eaten by stock will result in death in a few minutes. Thus 

 it is necessary for the extermination of the species and the safety of human 

 beings as well as animals to destroy all portions of poisonous perennials 

 by the quickest means possible. 



SPRAYING: Chemical sprays may be used to advantage; they are 

 economical and effective in most cases. Plants with rough leaves are 

 most susceptible, as the spray clings to the surface more readily. Smooth 

 leaves shed the spray before it has time to take full effect. The spray 

 should be applied in a fine mist on a bright clear day when there is no 

 likelihood of rain undoing the work. Spraying is most effective when the 

 plants are young and succulent, that is, just before they flower or in their 

 first bloom. 



COMMON SALT OR SODIUM CHLORIDE: Common salt is one of the 

 cheapest and safest sprays to use. It is most destructive when applied 

 in hot dry weather, as it absorbs the moisture from the plants and the 

 surrounding soil to such an extent that the plants die of thirst. A solution 

 of 150 pounds to 60 gallons of water may be used, or where all vegetation 

 is to be destroyed it may be applied in the form of hot brine, of such a 

 strength as to show crystals on its surface. 



