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Sorghum spp.

Johnsongrasses, milos, sudangrasses, and allies

Poaceae

Africa, Asia, and Australia (tropics and subtropics)

Drought Tolerant

SunFull Sun

WaterLow · drought-tolerant

HardinessZones 6–11

Overview

Sorghum spp. is a genus of about 25 species of annual and perennial grasses in the family Poaceae, native to warm regions of Africa, Asia, and Australia. Plants grow 2-13 ft (0.6-4 m) tall on stout, often solid stems, with broad, flat leaf blades 1-3 in (2.5-8 cm) wide and large, branched seed panicles at the top. S. bicolor is a major cereal grown worldwide for grain, syrup, forage, and broom fibers, while S. halepense, Johnson grass, is a rhizomatous perennial that has become an invasive weed across warm regions. The panicles carry many small spikelets that ripen from green to red, brown, or tan grain. Young, wilted, or frost-damaged foliage can accumulate cyanogenic compounds and nitrates that poison grazing livestock. Most species tolerate heat and drought and grow in a wide range of soils. The rhizomatous perennials spread aggressively and are hard to remove once established.

Native Range

Sorghum spp. is native to Africa, with additional species in Asia, the Middle East, and Australia. The cultivated grain sorghum S. bicolor was domesticated in northeastern Africa. Several wild and weedy species have spread to warm regions worldwide.

Suggested Uses

Grown as a grain, syrup, forage, and biofuel crop, and as broomcorn for brush fibers. Ornamental forms with red or black seed heads appear in cut and dried arrangements and as tall annual screens. The seed heads supply food for grain-eating birds.

How to Identify

Look for tall, robust grasses with stout stems, broad flat blades, and a large terminal panicle of paired spikelets. The grain ripens in open or compact heads in shades of red, brown, or tan. Johnson grass and other perennials can be recognized by their stout, spreading rhizomes, which annual grain sorghum lacks.

Appearance

Size & Dimensions

Height2' - 13'

Width/Spread1' - 3'

Colors

Flower Colors

red

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~6 weeks

Summer Fall

Flowering and grain set occur in summer and autumn, generally July to October, about two to four months after sowing in annual types. The wind-pollinated panicles shed pollen over one to two weeks. Perennial species flower repeatedly through the warm season.

Detailed Descriptions

Flower Description

green maturing to red, brown, or tan

Foliage Description

green

Growing Conditions

Sun Requirements

SunFull Sun

Requires 6-12 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.5 - 7.5(Neutral)

357912

Soil Types

loam clay sand silt

Drainagewell drained

Water & Climate

Water Needs

Low

Frost Tolerance

tender

Time to Maturity

3-4 months

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Plants grow in full sun and warm soil with a pH near 5.5 to 7.5, tolerating heat, drought, and poor or heavy soils more readily than many cereals. Annual grain and forage types are sown after the soil warms in late spring and harvested in autumn. Growth slows and foliage risks cyanide buildup under drought stress or after frost. Established plants need little water once rooted. Perennial species spread by rhizome and are contained where they are not wanted as a crop.

Pruning

Annual types are cut at harvest once the grain or forage matures, and stubble is cleared after the season. Forage sorghum is mown or grazed when tall, then allowed to regrow. Johnson grass and other perennials are mown or removed before seed set to limit spread.