grain sorghum
Sorghum bicolor · Poaceae
grain sorghum (Sorghum bicolor) is a annual grass or grass-like plant in the Poaceae family. It is introduced to North America rather than native. USDA records it as hardy in zone 11 and warmer, down to about 47°F.
⚠ Allelopathic. USDA flags this plant as releasing compounds that can suppress the growth of plants near it. Give neighbours extra room, and expect some companions to struggle regardless of how well their conditions match.
Both flags are quoted from USDA PLANTS, not inferred.
At a glance
| Type | graminoid USDA |
|---|---|
| Lifecycle | annual USDA |
| Native status | introduced USDA |
| Mature height | 8 ft USDA |
| Light | full-sun USDA |
| Water need | medium USDA |
| Growth rate | rapid USDA |
| Soil pH | 5.5–7.5 USDA |
| Bloom | August–September USDA |
| Flower color | Yellow USDA |
| Hardiness zones | 11 and warmer USDA |
| Guild layer | understory Derived |
| Nursery availability | Routinely Available USDA |
USDA quoted from the USDA PLANTS database · Derived computed by a fixed rule from those columns. No value on this page is estimated.
Growing conditions
It needs full sun. USDA rates it as having moderate water needs. Its drought tolerance is rated high. It will not tolerate waterlogged soil — USDA rates its anaerobic tolerance as none. It is recorded on soils from pH 5.5 to 7.5 — a broad range that spans acidic through mildly alkaline ground. Its cold limit is zone 11.
Size and growth
At maturity it reaches about 8 ft, making it a plant that will finish above head height. It grows quickly.
Bloom period
USDA records a bloom period of August through September. Flowers are yellow.
A flowering date, not a pollinator rating.
Foliage, flower and season
Summer foliage is green, coarse in texture. Its flowers are not conspicuous — a plant for form and foliage. Its fruit or seed heads are conspicuous, extending interest past flowering. Its active growth period is summer and fall.
What the site needs to provide
USDA records it across sites receiving 18 to 60 inches of annual precipitation. It needs at least 60 frost-free days to finish its season. It roots to at least 12 inches. Fertility requirement: high.
Propagating it
Seed is the only propagation method USDA lists. Division and cuttings are not listed as options. USDA records no cold-stratification requirement, so seed should germinate without a chilling period. Its seed spreads at a slow rate. It does not spread vegetatively, so it will stay where you put it.
Resilience and wildlife
Browsing animals find it moderately palatable, so expect deer and rabbits to take an interest. Its fire tolerance is rated low. Its growth form is recorded as bunch.
Role in a guild
Understory. In a layered planting this is the layer beneath the canopy, tall enough to hold structure but shaded from above. The layer is derived by a fixed rule from growth habit and mature height.
Tags
Related plants
Others in Sorghum
- sorghum Sorghum bicolor
- Sudangrass Sorghum bicolor
- Johnsongrass Sorghum halepense
Similar role and hardiness
- vegetable hummingbird Sesbania grandiflora
Where this data comes from
Every value on this page comes from the USDA PLANTS database record for symbol SOBIB, or is computed from those values by a fixed rule. Nothing here is estimated or model-generated. Where USDA publishes no value, this page omits the claim rather than filling the gap.
- Quoted from USDA PLANTS: active growth period, Allelopathy, Bloom, Bloom end, browse palatability, cold stratification, Drought tolerance, Edible, fall conspicuous, fertility requirement, fire tolerance, Flower color, flower conspicuous, foliage color, foliage porosity winter, foliage texture, frost free days min, fruit conspicuous, growth form, Growth rate, Hardiness zones, Lifecycle, Light, Mature height, Minimum temperature, Native status, Nitrogen fixation, Nursery availability, precipitation max in, precipitation min in, propagation, resprout ability, root depth in, seed spread rate, Soil pH, Soil pH (upper), Tolerance of wet soil, Toxicity, Type, vegetative spread rate, Water need.
- Derived by a fixed rule from those columns: Guild layer.
Read our full data sources and methodology.
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