24 The Colorado Experiment Station 
color or stain some objects, especially those that are light-colored 
or which contain compounds of tannin. 
Amount Required .—In the experiments carried on by the 
writer it was found that 1 gallon of the solution of iron sulphate 
would cover 100 to 150 square feet of lawn surface. More of the 
spray was required to do a thorough job when the grass was high 
than after it had been recently cut, hence it is a matter of econ¬ 
omy to mow the lawn just before each application. 
Use of Dry Iron Sulphate .—This method of using the iron sul¬ 
phate, while about equally effective with the spray, was found to be 
much more expensive than the lat¬ 
ter, due to the larger amount re¬ 
quired to secure equally good re¬ 
sults. Injury to the grass is more 
apt to occur than with a spray. 
The granular iron sulphate can 
be readily applied by using a 
tin can or small covered pail with 
the bottom punched full of nail 
holes, which permits of its being 
used as a large shaker. 
Gasoline, Kerosene and Creo¬ 
sote .—Gasoline forms a very ef¬ 
fective herbicide for killing dan¬ 
delions, but its cost is apt to be 
prohibitive except on small areas 
and where the plants are few in 
number. About one teaspoonful 
of the liquid applied in the cen¬ 
ter. of the plant is usually suffi¬ 
cient, although large plants often 
require twice that amount. The 
treated plants soon wilt and in a 
day or two appear quite dead. In 
manv cases the entire root will be 
•/ 
found in a shriveled condition and can be pulled out of the ground. 
The gasoline will also kill the grass around each treated plant, 
the spots often being two or three inches across. As the gasoline 
soon evaporates, the grass may re-occupy these spots after a few 
weeks’ time, but where a great many plants are present, this in¬ 
jury becomes rather serious in the aggregate. 
The cost of clearing a lawn from dandelions with this method 
varies greatly, being almost directly in proportion to the number 
of weeds present. It is a useful method to employ where the 
Fig - . 13. Tools used by the writer 
in digging dandelions. The pocket- 
knife is employed principally as a 
makeshift when the other tools are 
not at hand. The right-hand imple¬ 
ment, made from an old buggy 
spring, is the chief reliance for se¬ 
rious and effective work. 
