Sorghum is a tall, grass-like crop that looks similar to corn when young but develops a distinctive cluster of seeds at its top instead of an ear. Depending on the variety, it stands anywhere from about 4 feet to well over 8 feet tall at maturity, with broad leaves arching out from a central stalk. Here’s what to expect at every stage, from seedling to harvest-ready grain.
The Overall Shape of the Plant
Sorghum belongs to the grass family, and at first glance it resembles a stocky corn plant. A single upright stalk grows from the ground, and flat, strap-like leaves alternate on either side of it. The leaves are typically about 2 to 3 inches wide with a prominent white midrib running down the center. Unlike corn, sorghum doesn’t produce a side ear wrapped in husks. Instead, a large seed head (called a panicle) emerges from the very top of the plant, giving it a shape that’s closer to a giant ornamental grass.
Modern grain sorghum hybrids generally reach 4 to 6 feet tall. Trial data from Mississippi in 2025 recorded plant heights ranging from 47 inches to 72 inches across commercial hybrids, measured from soil level to the top of the seed head. Sweet sorghum and forage varieties grow considerably taller, sometimes exceeding 10 to 12 feet, with thinner, juicier stalks.
What Seedlings Look Like
Sorghum seeds are small and round, typically 2 to 4.5 millimeters in diameter. After planting, the first shoot pushes through the soil surface within 3 to 10 days. The emerging seedling looks like a single pale-green spike, similar to a young corn or grass shoot. By about 10 days after emergence, the plant has three fully expanded leaves. Each leaf is counted once you can see its collar, the small band where the leaf blade meets the stem.
At roughly three weeks after emergence, the plant has five fully expanded leaves and its root system is growing fast. Roots forming at the lowest stem nodes can actually push the earliest leaves off the plant, so don’t be surprised if the bottom leaves disappear. At this stage, sorghum is still short and looks a lot like a clump of wide-bladed grass.
Vegetative Growth: Stalks and Leaves Fill In
Around 30 days after emergence, the growing point inside the stalk shifts from producing leaves to forming the seed head. You can’t see this change from the outside, but the plant’s overall look starts to change. The stalk thickens and elongates quickly, and more leaves unfurl. A mature sorghum plant typically produces 14 to 17 leaves total, though this varies by variety.
As the plant gets taller, you’ll notice it looks increasingly like corn but with a few differences. Sorghum leaves tend to be slightly narrower and waxier, often with a bluish-green tint. The stalk is solid and pithy rather than hollow, and in sweet sorghum types, snapping a stalk open reveals moist, sugary tissue similar to sugarcane. One distinctive feature as the plant matures: green prop roots may emerge from the lower stem nodes above the soil line, looking like small aerial roots reaching toward the ground. These eventually anchor into the soil and help brace the plant.
The Seed Head Emerges
The most visually dramatic phase is “boot stage,” when the developing seed head swells inside the uppermost leaf sheath, creating a noticeable bulge near the top of the plant. Within a few days the panicle pushes out and opens. This is when sorghum stops looking like corn and takes on its own identity.
Sorghum panicles come in a surprising range of shapes. Grain sorghum varieties tend to have compact, oval or elliptical heads packed tightly with seeds, somewhat resembling a dense pine cone. Forage types typically have open, loose panicles with branches that spread outward or droop. Broomcorn sorghum, historically used to make brooms, has long spreading branches with very little grain. If you see sorghum growing in a field, the compact, upright head on a shorter plant is almost certainly grain sorghum.
Half-bloom, when about half the tiny flowers on the panicle have opened, arrives roughly 60 days after emergence. The individual flowers are small and not showy, but you may notice yellow pollen-producing structures dangling from the head during this window.
Seed Colors and Appearance
As the seeds fill and mature, the panicle takes on color, and this is where sorghum’s diversity really shows. Seed color ranges widely across varieties: white, chalky white, straw, yellow, light brown, red, reddish brown, dark brown, purple, and even black. Some varieties produce variegated or mixed-color seeds. The most common commercial grain sorghum in the U.S. tends toward reddish-brown or bronze, but white-seeded varieties are popular for food-grade sorghum.
Each individual kernel is round and small, sitting in a tiny cup-like structure on the panicle branch. From a distance, a field of maturing grain sorghum with reddish heads on green stalks has a warm, rust-toned look that’s easy to distinguish from the golden yellow of ripe wheat or the green tassels of corn.
What Mature, Harvest-Ready Sorghum Looks Like
As the plant reaches physiological maturity, the leaves begin to yellow and dry from the bottom up, much like corn in autumn. The seed head darkens to its final color, and the seeds harden. The reliable sign that sorghum has finished filling its grain is the formation of a “black layer,” a thin dark line visible at the base of each kernel where it attaches to the seed head. At this point, the seed contains about 30 to 35 percent moisture and has reached its maximum weight.
Farmers typically wait for the grain to dry down further before combining, so you’ll often see sorghum standing in fields looking completely brown and dry, with stiff upright stalks and heavy seed heads bending slightly under their own weight. In some varieties the heads nod or droop as they dry, giving the field a slightly different profile than the bolt-upright look of earlier growth stages.
How Different Types Compare
If you’re driving past a sorghum field and wondering which type you’re looking at, a few visual cues help:
- Grain sorghum is relatively short (4 to 6 feet), with a thick stalk and a dense, compact seed head. This is the most common type grown in the U.S. Great Plains.
- Sweet sorghum is tall, often 8 feet or more, with thinner stems that are juicy and sweet inside. Its seed heads are smaller and more open. It’s grown for syrup production.
- Forage sorghum is also tall and leafy, bred to produce maximum plant material for livestock feed. Its panicles are loose and open rather than packed tight.
- Broomcorn has long, fibrous panicle branches that fan outward, with very little grain. It looks dramatically different from the compact-headed grain types.
How Sorghum Differs From Corn at a Glance
Since sorghum and corn grow side by side in many farming regions, it helps to know the quick differences. Sorghum leaves have a waxier surface and a more bluish cast. The stalks are typically thinner and solid rather than pithy-hollow. The biggest giveaway is at the top: corn produces a wispy tassel that releases pollen, with ears growing partway down the stalk. Sorghum produces its entire seed crop in a single head at the very top of the plant, with no separate ear. From a distance, a sorghum field has a more uniform, flat-topped look compared to the taller, tassel-topped silhouette of corn.