﻿WEEDS 
  

  

  339 
  

  

  readily 
  transported 
  seeds, 
  such 
  as 
  golden 
  rod, 
  thistles, 
  prickly 
  

   lettuce, 
  and 
  milkweeds, 
  to 
  seed 
  all 
  adjoining 
  parts 
  of 
  the 
  farm. 
  

  

  Many 
  useful 
  plants 
  and 
  still 
  more 
  harmful 
  ones 
  spread 
  by 
  

   vegetative 
  means 
  so 
  as 
  to 
  overrun 
  neighboring 
  ground. 
  In 
  

   this 
  way 
  a 
  blackberry 
  patch 
  may 
  spread 
  by 
  the 
  root 
  so 
  as 
  to 
  

   become 
  a 
  nuisance, 
  and 
  black 
  raspberry 
  bushes 
  will 
  travel 
  by 
  

   means 
  of 
  their 
  long 
  root- 
  

   ing 
  branches 
  (fig. 
  72) 
  so 
  

   as 
  to 
  cover 
  much 
  ground. 
  

   Couch 
  grass, 
  or 
  quack 
  

   grass 
  (fig. 
  245), 
  growing 
  

   beside 
  a 
  cultivated 
  field 
  

   or 
  garden 
  will 
  soon 
  spread 
  

   into 
  the 
  cultivated 
  soil 
  

   by 
  means 
  of 
  its 
  vigorous 
  

   rootstocks. 
  

  

  Methods 
  of 
  destroying 
  

   weeds 
  cannot 
  be 
  treated 
  

   in 
  detail 
  in 
  a 
  textbook 
  

   on 
  botany, 
  though 
  a 
  few 
  

   words 
  may 
  be 
  given 
  to 
  

   the 
  subject. 
  Weeds 
  which 
  

   have 
  gone 
  to 
  seed 
  should 
  

   not 
  be 
  plowed 
  or 
  spaded 
  

   under, 
  but 
  should 
  be 
  

   burned 
  when 
  dry. 
  It 
  will 
  

   be 
  found 
  well 
  worth 
  while 
  

   to 
  rake 
  away 
  from 
  fences 
  

   and 
  burn 
  all 
  accumulations 
  of 
  tumbleweeds. 
  Wild 
  mustard, 
  

   which 
  is 
  a 
  very 
  troublesome 
  weed 
  in 
  fields 
  of 
  the 
  small 
  grains, 
  

   is 
  readily 
  killed 
  by 
  spraying 
  with 
  a 
  solution 
  of 
  copper 
  sulphate 
  

   or 
  iron 
  sulphate. 
  Weedy 
  lawns 
  are 
  sometimes 
  improved 
  by 
  

   very 
  careful 
  salting, 
  which 
  does 
  not 
  injure 
  the 
  grass. 
  Gravel 
  

   walks 
  may 
  be 
  cleared 
  of 
  weeds 
  by 
  watering 
  them 
  with 
  a 
  highly 
  

   poisonous 
  solution 
  of 
  sodium 
  arsenate 
  or 
  of 
  crude 
  carbolic 
  acid. 
  

   Rotation 
  of 
  crops 
  (that 
  is, 
  following 
  the 
  crop 
  of 
  one 
  year 
  by 
  a 
  

  

  FIG. 
  246. 
  Wild 
  oats, 
  a 
  grass 
  belonging 
  to 
  

   the 
  same 
  genus 
  as 
  the 
  cultivated 
  oat 
  

  

  It 
  is 
  an 
  extremely 
  troublesome 
  weed, 
  espe- 
  

   cially 
  in 
  fields 
  of 
  the 
  small 
  grains. 
  After 
  

   "Farm 
  Weeds 
  of 
  Canada" 
  

  

  