As 12 to 15 seeds are planted to the hill it is always necessary to thin out some of the hills. Roots of larger plants become matted and it is difficult to pull out one of them without injuring the others. As in thinning corn, thinning hemp is best done when the ground is fairly moist. If the plants are a foot or more high, either wait for a rain before thinning, or cut out the plants instead of pulling them. Cultivate the crop both ways as soon as the plants are 2 to 4 inches high, even if it is impractical to get close to the hills.
Hemp grows so fast that it usually chokes out the weeds in the hills.
Use a riding cultivator equipped with good fenders. Because the rows are so far apart, run through the middles with a one-horse cultivator. Cut out the male plants. Because flowers on the female plant produce no pollen they must be fertilized by pollen from the male plants in order to make seed. After the pollen is shed and the male plants begin to die cut them out to give the female plants more room to develop.