To grow sorghum in the garden, fertilize and prepare the soil on flat ground or in a bed, and plant seeds 1 to 2 inches deep at a rate of one seed every 4 inches in rows 20 to 30 inches apart. Plant seeds deeper in lighter soils.
Sorghum requires warm soil to germinate, so plan to plant in May or June for best results. Mix an organic fertilizer into the soil, and prepare the soil with a motorized or manual plow or other tool, plowing as deep as possible. If you choose not to fertilize the soil prior to planting, apply a fertilizer to the 2 to 3 inches of soil surrounding the seeds. Smooth the soil before planting the rows. Keep in mind that a large plot is not necessary as sorghum is self-fertile and doesn't require cross-pollination.
After seeding, keep the soil well-watered but not drenched, and weed the area until the sprouts have grown large enough to dominate the area. Apply a high-nitrogen liquid fertilizer six weeks after planting to encourage growth. Sorghum grows best in areas where summertime temperatures often pass 90 degrees Fahrenheit, and it is more resistant to flooding and drought compared to corn. Harvest the sorghum when rust-colored seeds bunch at the top of the plant in mid-autumn.