174 



FRIENDS AND ENEMIES OF PLANTS 



are classed as weeds. Thus our ordinary white clover when grow- 

 ing upon our lawns might be classed as grass, but when found grow- 

 ing in the garden in our onion or lettuce bed would be classed 

 as a weed. Many of our present cultivated plants were once 

 wild plants, but have been improved by cultivation and selection 

 until they have been brought up to their present state of perfec- 

 tion. It is also possible that many other plants which we now 

 regard as useless weeds may be found to have some useful property 



and may sometime be classed 

 among our valuable cultivated 

 crops. 



Burdock. 



Cocklebur. 



Good farming involves the control of weeds. Some of the most 

 effective means of control are: good rotation courses; clean til- 

 lage; cleaning up of waste places in which weeds breed; care in the 

 choice of clean seed; care to see that the manure does not carry 

 seeds; alertness to recognize new weeds when they begin to in- 

 vade the neighborhood. 



Why we should prevent the Growth of Weeds. There are many 

 reasons why we should not allow weeds to obtain a foothold 

 among our crops; some of them may be briefly stated as follows: 



