Potato Growing in Colorado 
15 
see to it that all hills that do not come up to the standard, or to 
the average, are removed and destroyed. This is the most effective 
method of keeping up the purity of the seed, as well as the produc¬ 
tiveness. Further, it eliminates diseased plants and those that show 
a predisposition to become infected. In fact, it is advisable to fol¬ 
low the method of roguing not only in the seed plot, but in the 
general field, for considerable improvement can be brought about 
by a system of roguing in any field of potatoes, whether grown for 
seed exclusively, or for the general market. 
The time and effort expended on this work will be more than 
repaid in a higher grade of potatoes, besides eliminating diseases 
in the field and tubers. 
CULTIVATING AND HILLING 
There is no crop grown on the farm that requires better culti¬ 
vation or that responds more readily to good cultivation and favor¬ 
able soil conditions than potatoes. Being a tuber-producing plant, 
the shape and size of the tubers are adversely affected by a hard, 
lumpy, and poorly prepared seed-bed. The practice of preparing 
the soil after planting and during the growing season should be 
discouraged—as no amount of after-cultivation can properly prepare 
the land without disturbing the growing crop. Not only should the 
surface soil be in fine tilth, but also the soil below, to the depth of 
ten inches. In loose, mellow soil, the feeding roots of the potatoes 
will often penetrate the soil to a depth of from twenty-four to 
thirty-six inches. 
Cultivation should start soon after planting, using an ordinary 
spike-toothed harrow, going' over the land every few days. When 
the potatoes are above ground, harrowing should be continued, but 
the teeth of the harrow should be set slanting so as not to* tear up the 
sprouts. This harrowing will keep the soil in fine tilth and conserve 
the moisture in the soil, besides keeping the field free from weeds. 
Ordinarily, at planting time, the soil should contain enough mois¬ 
ture for the potatoes to come up, without resorting to irrigation, 
especially if the land has been properly handled up to- this time. 
However, there may be seasons when this is impossible, and irriga¬ 
tion has to be given. 
Cultivation is more important than irrigation, and the grower 
should never substitute irrigation for cultivation. After the potatoes 
are up and too' tall for the harrow,, the cultivator should be started 
and kept going until the vines interfere. 
Hilling .—Hilling is almost universal among potato growers in 
the State. This is especially true on the plains east of the mountains 
where this practice is possibly carried to an extreme. The prac- 
