How to Grow Sudangrass
Wikimedia Commons
Sudangrass
Sorghum bicolor subsp. drummondii
grassSudangrass is a warm-season annual grass that grows rapidly and produces abundant foliage, commonly used as livestock forage and cover crop. It is a hybrid derivative of sorghum that tolerates heat and drought while accumulating biomass quickly. The plant can reach 3-6 feet tall and is valued for its nutritional content and soil-building capabilities.
Looking for a specific variety?
When should you plant Sudangrass in your zone?
Get a personalized planting timeline — when to start seeds, transplant, and harvest — based on your USDA zone and local frost dates. Free to start.
Example Sudangrass timeline · Pittsburgh, PA (Zone 6b)
-
Plant Sudangrass
Around Apr 17Near Pittsburgh's average last spring frost.
-
Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
-
Harvest Sudangrass
Around Jun 1≈ 45 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Sudangrass dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 5-10; best production in zones 6-9
Sign up free to see if Sudangrass grows in your zone — and get a personalized planting timeline.
Get my Sudangrass timeline →Growth Stages
Germination & Seedling
2-3 weeksSeeds sprout within 7-10 days in warm soil. Young seedlings emerge with two linear leaves and establish a fibrous root system.
Soil temperature must be at least 60°F (ideally 70°F+). Keep seedbed moist but not waterlogged. Thin seedlings to proper spacing once 2-3 inches tall.
Vegetative Growth
3-6 weeksPlant rapidly develops tillers (shoots) and accumulates leaf biomass. Stem elongation accelerates in warm weather.
Monitor for nitrate accumulation if highly fertilized; ensure adequate water during dry spells. Remove competing weeds. Begin first grazing or cutting at 12-18 inches tall.
Boot to Heading
2-3 weeksInflorescence (seed head) begins to emerge from the boot stage (leaf sheath) into the heading stage, with plume appearance.
Quality and digestibility of forage peak just before heading. Plan second cutting or grazing at this stage for best nutritional value. Reduced rainfall/water needs at this point.
Flowering & Grain Fill
2-4 weeksFlowers open and pollen is shed; grain begins to develop. Plant energy shifts from leaf production to reproduction.
Forage quality declines rapidly. If harvesting for hay, cut before this stage. If allowing to mature for seed, reduce nitrogen inputs. Watch for lodging in windy conditions.
Seed Maturity & Senescence
2-3 weeks or end of seasonGrain hardens and darkens; leaves yellow and senesce. Plant becomes dormant or dies in fall as a true annual.
Stop all irrigation. If harvesting seed, wait until grain reaches hard dough stage. Allow plant residue to remain for soil improvement or remove for next crop.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
-
Scout regularly; apply insecticidal soap or spinosad if populations exceed threshold; encourage natural predators like parasitic wasps
-
Use resistant varieties; apply kaolin clay or neem oil; remove crop residue to reduce overwintering habitat
-
Plant early-maturing varieties; avoid late plantings; remove infested seed heads and debris
-
Plant resistant or tolerant varieties; spray insecticidal soap or horticultural oil; release natural predators
-
Ensure good drainage; rotate crops; plant disease-resistant varieties; avoid waterlogging
Uses
Livestock Forage & Feed
CulinarySudangrass is a premier forage crop for cattle, sheep, goats, and horses, either grazed directly or harvested for hay and silage. Its high palatability and rapid regrowth make it ideal for rotational grazing systems. [source]
Soil Improvement & Cover Crop
HouseholdSudangrass accumulates significant biomass and organic matter, improving soil structure and fertility when incorporated. Its deep root system helps break compacted soils and reduce erosion. [source]
Allelopathic Weed Suppression
MedicinalSudangrass produces allelopathic compounds (sorgholeone) that inhibit the growth of competing weeds and certain pathogens. This natural herbicidal property reduces the need for chemical weed control in rotation systems. [source]
Biofuel & Biomass Production
CraftSudangrass is used to produce bioenergy, biofuel feedstock, and industrial biomass due to its high cellulose content and fast growth rate. Multiple harvests per season increase overall energy yield. [source]
Wildlife Habitat & Erosion Control
WildlifeDense stands of Sudangrass provide cover and nesting habitat for ground-nesting birds and small wildlife while stabilizing banks and preventing soil erosion on sloping terrain. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
For grazing: Allow plants to reach 12-18 inches before first grazing; remove animals when plants are grazed to 3-4 inches to allow regrowth. For hay/silage: Cut at boot to early-heading stage (just before flowering) for maximum nutritional value and digestibility; typically occurs 45-60 days after planting. For seed: Allow plants to mature fully; harvest when grain reaches hard dough stage (late milk stage); combine or thresh dried plants. Multiple cuttings are possible in a single season in warm climates.
Fun Facts
- 🌱 Sudangrass can regrow multiple times from the same root system in a single season, often producing 2-4 cuttings in warm climates before frost.
- 🌱 The plant is known for its ability to tolerate both drought and poor soils that would stress many other crops, making it valuable in marginal agricultural lands.
- 🌱 Sudangrass produces a natural herbicide compound called sorgholeone that can persist in the soil, sometimes inhibiting the growth of subsequent crops; adequate decomposition time (2-4 weeks) is recommended before replanting susceptible species.
Gardening Terms
New to gardening? Learn about terms used in this guide:
Join 30,000 gardeners planning their gardens with LizPlants.
Get your personalized Sudangrass planting timeline
Tell us your zip code and we'll calculate exactly when to start Sudangrass seeds, transplant seedlings, and harvest — based on your USDA zone and local frost dates. Includes calendar reminders and printable task lists. Free to start.
Get my Sudangrass timeline →