Spread ¼ lb. of nitrogen fertilizer over 100 square feet of a well-drained, rich garden bed. Till the nitrogen into the soil to provide nutrients to the broomcorn. Tilling also breaks up any clumps in the soil so the broomcorn can root well.
Sow the broomcorn seeds 1 inch deep and space them 6 inches apart. Plant the rows 16 inches apart so the plants don't become overcrowded.
Water broomcorn one to two times a week. Irrigate in the cooler morning hours so the moisture can penetrate the soil before high afternoon heat causes it to evaporate. The broomcorn grows best in soils that are moist in the top 6 inches of their depth.
Weed between the young broom corn plants regularly until they are tall enough to shade out most new weed growth. Use a hoe to break up the top inch of soil between the plants or pull the weeds out by hand.
Harvest broom corn when the entire stalk turns green. Cut off the stalk near the base with a sharp knife. The plant begins producing seeds approximately five days after it turns green, rendering it unsuitable for use in brooms and decorative applications.