68 EXPERIMENT STATION. [Jan. 



We may therefore consider weed exterminators imder two 

 heads : those which particularly affect the root system and those 

 which affect only the foliage. Some of the latter type will be 

 dealt v/ith subsequently. The use of chemicals for killing 

 weeds is practical in many cases. They are useful, also for 

 killing ivy about stone walls, around houses and trees, on tennis 

 courts, driveways, etc. The writer has applied them on lawns 

 close to buildings, to save the expense of hand trimming. About 

 3 or 4 inches of the grass adjacent to a building may be treated 

 without any injury to the appearance of the lawn, and much 

 saving of labor in hand trimming results. In treating walks 

 care must be exercised in running the solution close to the 

 edge of the lawn and not touching the grass. Eor this pur- 

 pose the writer has used an ordinary sprinkling can with a 

 special attachment on the spout to confine the flow to narrow 

 limits. Tennis courts need, as a rule, to be treated only around 

 their edges, where the weeds and grass are more likely to come 

 in, and two or three treatments made on succeeding years 

 should keep the courts practically free from weeds. This 

 treatment is applicable to paved ditches, highways and drives, 

 and the difficulties arising from the grass growing on electric 

 railways, causing slippery rails, may be obviated by a treatment 

 of a narrow limit near the rails. Care should be exercised, 

 however, in using weed killers too extensively, especially near 

 the feeding roots of valuable shade trees. 



The writer has frequently treated walks near which shrub- 

 bery grew closely, as well as large trees, with arsenic com- 

 pounds, but in such cases there is a likelihood of injuring only 

 a small part of the root system, if any, and such injury would 

 be merely local, of course, and of small consequence. 



