Till the area where you plan to plant the Proso Millet with a tractor or large garden tiller. Prepare the ground by removing the clumps of grass with a rake. Start preparing the ground when the weather turns warm, around May. Make sure the ground is not sandy or coarse.
Spray the tilled area with a weed killer, such as 2, 4-D Amine. Make sure no weeds remain in the area by tilling the ground and applying weed killer for a second time after about two weeks.
Place the Proso Millet seed in the ground between the beginning of June and July, according to the climate. It is considered a late crop and grows best after soil temperatures reach 65 degrees.
Bury the seeds, with a planter or by hand, about 1 inch below the firm ground. Use between 20 and 30 pounds of Proso Millet seed per acre. Seeds grow well where they do not have competition with weeds, so ground preparation is very important.
Avoid over watering Proso Millet. It is a self-sufficient crop that generally does not require additional tilling or watering after seeds begin sprouting, which generally takes 20 days.