How to Grow Sudan Grass

iNaturalist

Sudan Grass

Sorghum bicolor subsp. drummondii

grass

Sudan grass is a warm-season annual grass closely related to sorghum, prized for its rapid growth and high forage yield. It produces tall, leafy stems with fine texture, making it excellent for hay, silage, and pasture. This heat and drought-tolerant crop is popular in agricultural systems for livestock feed and soil improvement.

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Example Sudan Grass timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Sudan Grass

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Sudan Grass

    Around Jun 26

    ≈ 70 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Sudan Grass dates for your own zip code.

Growing Conditions

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Sun: Full sun, minimum 8+ hours daily; performs best with unobstructed sunlight
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Water: Moderate to high water needs during growth; requires 15-25 inches annually. Drought-tolerant once established but responds well to irrigation. Water during dry spells for optimal yield.
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Spacing: 6-12 inches between plants in rows; rows 24-36 inches apart for mechanical cultivation inches
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Days to maturity: 70-100 days to boot stage; 90-120 days to soft dough stage for hay harvest
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Planting depth: 0.75-1.5 inches; plant after soil reaches 60°F (ideally 65-70°F)

Soil

Type: Well-draining loamy to clay loam soil
pH: 6.0-7.5
Amendments:
Compost Balanced NPK fertilizer (especially nitrogen) Lime if pH is below 6.0

Growing Zones

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Thrives in zones 5-10; best in zones 6-9 where frost-free period exceeds 90-120 days

5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a 10b

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Growth Stages

1

Germination & Seedling

2-3 weeks

Seeds emerge in 7-14 days; seedlings develop first true leaves and establish root system

Ensure consistent moisture for germination. Protect seedlings from birds. Thin seedlings to proper spacing if needed. Keep weed-free during this vulnerable stage.

2

Vegetative Growth

4-6 weeks

Rapid stem and leaf development; plants reach 24-36 inches tall with multiple tillers; deep root system develops

Apply nitrogen fertilizer to promote growth. Maintain consistent watering. Monitor for pests and weeds. Thin to final spacing if not done earlier.

3

Boot to Heading

2-3 weeks

Panicles begin emerging from boot (sheath). Stems reach full height (4-8 feet depending on variety); flowering begins

Reduce nitrogen to avoid lodging. Ensure adequate potassium for strength. Monitor moisture levels. This stage indicates readiness for early hay harvest if desired.

4

Flowering & Grain Development

3-4 weeks

Full panicle emergence; individual florets bloom; grain develops in soft dough to hard dough stage

Avoid major nitrogen applications now. Maintain adequate water if grain harvest intended. Monitor for head smut and other diseases. Most nutritious stage for pasture grazing.

5

Maturity & Harvest Ready

2-3 weeks

Panicles dry down; grain hardens; stems may yellow or brown depending on rainfall and frost; plant reaches full maturity

Reduce watering unless late rains expected. Harvest hay before hard freeze for best quality. For grain harvest, allow moisture to drop to 15-20%. Handle carefully to minimize seed shatter.

Companion Planting

Plan your garden →

Plant with:

Legumes (alfalfa, clover) Soybeans Cowpeas Buckwheat Vetch

Avoid planting near:

Johnsongrass (allelopathic competition) Corn (disease host competition) Wheat (disease host)

Common Pests

  • Monitor early season; use resistant varieties; parasitic wasps provide natural control; insecticidal soap if severe

  • Inspect for webbing and defoliation; Bacillus thuringiensis (Bt) spray; allow natural predators; avoid broad-spectrum insecticides

  • Plant resistant varieties; practice crop rotation; seed treatment fungicides; avoid excessive irrigation at heading

  • Scout during boot to milk stage; early or late planting to avoid peak midge activity; resistant varieties available

  • Monitor for wilting; remove nearby weedy grasses; natural parasites; tolerant of some damage in forage systems

Uses

🍳

Livestock Feed & Forage

Culinary

Sudan grass is a premium forage crop used for hay, silage, and pasture grazing across North America. Its high digestibility and palatability make it an excellent feed for cattle, sheep, goats, and other livestock. [source]

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Soil Conservation & Erosion Control

Household

The dense root system and rapid canopy establishment make Sudan grass ideal for erosion control on slopes and streambanks. It stabilizes soil quickly and can be incorporated for organic matter improvement. [source]

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Rotation & Soil Health

Household

Used in crop rotation systems to break disease cycles, suppress weeds, and suppress parasitic nematodes. Its allelopathic properties can inhibit problem weeds when incorporated into soil. [source]

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Wildlife Food & Habitat

Wildlife

Seeds provide excellent food source for birds and small mammals in late season. The tall stems create cover for ground-nesting birds and beneficial insects. [source]

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Drought-Tolerant Alternative Crop

Household

Its exceptional drought tolerance and heat resistance make Sudan grass valuable in water-limited regions and during dry years. Continues producing forage when conventional crops fail. [source]

Harvest Tips

For hay: Cut at boot to early head stage (60-90 days) when leaves still have maximum nutritional value; moisture should be 40-60% for baling. For silage: Harvest at soft dough stage (90-100 days) with 65-75% moisture. For grain: Harvest when moisture drops to 15-20%; may require a combine. For pasture grazing: Graze when 18-24 inches tall; allow 6-8 inches regrowth before next grazing cycle. Multiple harvests possible with proper management.

Fun Facts

  • 🌱 Sudan grass can produce 3-5 tons of dry hay per acre in a single season, making it one of the highest-yielding forage crops available.
  • 🌱 The plant name 'Sudan grass' originated from its discovery in Sudan, Africa, though it is now grown worldwide and is a major crop in the American Great Plains and Midwest.
  • 🌱 Sudan grass is highly palatable to livestock and reportedly improves milk flavor when used as feed, with some dairy farmers reporting sweeter-tasting milk from grass-fed herds.

Gardening Terms

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