Sometimes sown in mixtures with sweet clover or roughpeas. Johnsongrass responds to fertilization on most soils, especially on eroded and depleted ones. Planting with a legume is another way to increase the nitrogen content in soil for johnsongrass. Harvesting Johnsongrass is cut for hay when flower-heads are still in the boot stage. Coarse stems dry slowly and thorough curing is necessary to produce good hay.
Seeds are dormant when first mature and require a number of months to after-ripen.
Even when they do not germinate completely until alternating cold-warm temperatures are available in a warm area. Eradication is sometimes a serious problem. Pasturing has been recognized as one method to control this grass. Mowing gives much the same effect. An average plant produced from a single seed can produce more than 170 culms, ca 20 m of rhizomes and 1.7 kg of seed per season, depending on soil fertility, moisture, and space.