Johnson Grass

Description — Upright perennial grass, reproducing by rhizomes and seeds. Well adapted to compete with crop plants. Stems up to 6 to 8 feet high or more, from a freely branching fibrous root system, which produces extensive rhizomes within six weeks of generation. Leaves alternate, simple, relatively wide and long. Spikelets 1-flowered, in groups of 3, in large open panicles. Fruit a caryopsis or grain, finely striate, reddish-brown with two knobbed rachillae extending upward from the base of the seed. Flowers from May until frost and seeds to frost.

Adaptation — Found especially on rich soil, johnson grass is a common weed in in cropland, roadsides, ditches, and field margins. Troublesome in crops on overflow bottoms, it often grows in moist ground. The largest acreage of johnson grass infestation in southeast and southwest Kansas.

Management options

 1. Prevention —reduce infestations by planting seed free of johnson grass seed, using livestock feed free of this noxious weed, and cleaning machinery before leaving infested areas.

2. Cultural Control — Infestations by be reduced by planting small grain and using intensive tillage as needed after harvest. Hoeing can be used as needed to control johnson grass in yards, flower gardens and among shrubs. Mowing as needed and intensive grazing can be used to control this noxious weed in established grass.

3. Biological Controls — None

4. Recommended Treatments:

 Roundup (Glyphosate) .5 gallon/acre

Oust (Sulometuron) 6 to 12 oz/acre (2 to 5 oz/acre for short term control)

Roundup(Glyphosate) + Oust (Sulfmeturon) – 2oz Oust + .5 gallon Roundup/acre

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