The sesame plant is a tall, upright annual that grows anywhere from 2 to 6 feet high, with a sturdy square stem, broad leaves, and delicate bell-shaped flowers that line the stalk. It looks nothing like what most people expect from the tiny seeds on a hamburger bun. If you saw one growing in a field, you might mistake it for a decorative garden plant before guessing it was a food crop.
Stem and Overall Shape
Sesame grows as a single erect stem or with several branches, depending on the variety. The stem is slightly square in cross-section and covered in fine hairs, giving it a soft, almost fuzzy texture. Most plants reach 3 to 5 feet tall under typical growing conditions, though some varieties stretch past 6 feet in warm climates with a long season. The overall silhouette is narrow and columnar, not bushy, which is why sesame fields can look dense and uniform from a distance.
Unbranched varieties tend to look like a single green pole covered in leaves and pods, while branched types spread outward with several side stems, each producing its own set of flowers and seed capsules. The branching pattern even extends underground: unbranched varieties develop a stronger, straighter taproot, while branched types produce more fine lateral roots spreading outward.
Leaves
The leaves are one of sesame’s more distinctive features because they change shape as you move up the plant. Lower leaves are broad, sometimes lobed with three segments, and can be several inches across. Higher on the stem, the leaves become narrower and more lance-shaped, with smooth or slightly toothed edges. They grow in pairs or alternate along the stem, attaching at obvious nodes. The overall color is a medium green, and the leaf surface has the same soft hairiness as the stem.
Flowers
Sesame flowers are small, tubular, and bell-shaped, about 1 to 2 inches long. They grow individually from the leaf axils, which are the points where a leaf stalk meets the main stem. Most varieties produce white or pale pink flowers, though some have lavender or light purple blooms with darker streaks inside the throat of the bell. Each flower looks a bit like a small foxglove or snapdragon blossom. They open progressively from the bottom of the plant upward, so a mature sesame plant in full bloom will have open flowers in the middle, spent flowers below, and unopened buds near the top.
Seed Pods
After the flowers are pollinated, each one develops into a small, oblong seed capsule about 1 to 1.5 inches long. These pods are green while developing and line the stem in neat vertical rows, tucked close against it. Each capsule is divided into internal chambers packed with the tiny flat seeds you recognize from the grocery store.
As the pods dry and mature, they turn from green to tan or brown. This is when the plant’s most important (and frustrating, for farmers) feature kicks in: the pods split open along their seams and release the seeds. This natural shattering is so effective that it causes significant yield loss in commercial production and is one of the main reasons sesame has resisted large-scale mechanized harvesting. The splitting happens because a specialized layer of cells along the pod’s seam weakens and breaks apart as the fruit dries. This is actually the origin of the phrase “open sesame,” a reference to how dramatically the pods pop open.
A fully mature sesame plant with drying pods looks strikingly architectural, like a tall stick studded with dozens of small, pointed capsules arranged in orderly columns.
Root System
Below ground, sesame develops a strong central taproot with many fine side roots branching off it. Most of the root mass sits in the top 12 inches of soil, but the taproot itself typically reaches its maximum length around 75 days after planting. In deep, loose soils, sesame roots have been observed reaching down to 6 feet, which helps explain the plant’s reputation for drought tolerance. That deep taproot lets it pull water from soil layers that shallower-rooted crops can’t access.
Plants That Look Similar
If you’re trying to identify sesame in a garden or field, the plant most commonly confused with it is devil’s claw (sometimes called ram’s horn). Both have tubular flowers and produce distinctive seed pods. The easiest way to tell them apart: devil’s claw flowers grow in clusters of 8 to 20, are noticeably larger (up to 2 inches long), and produce dramatically long, curved seed pods reaching 4 to 8 inches with horn-like tips that split in half. Sesame flowers grow alone at each leaf node, are smaller, and produce compact pods only 1 to 1.5 inches long with a short, straight tip.
Sesame also bears a passing resemblance to foxglove or some species of salvia when in bloom, but the combination of the square stem, changing leaf shapes, and orderly rows of pods along the stalk is unique to sesame.
What It Looks Like Through the Season
In its first few weeks, sesame is a modest-looking seedling with a pair of rounded starter leaves followed by broader true leaves. Growth is rapid once temperatures are consistently warm, with roots elongating as fast as about an inch per day in the first week and a half after planting. By midsummer, the plant is waist-high or taller with a full canopy of leaves.
Flowering typically begins about 6 to 8 weeks after planting and continues for several weeks as new blooms open progressively up the stem. During this stage, the plant is at its most visually striking, with flowers and developing pods visible simultaneously. As the season winds down, the leaves yellow and drop, the stem dries to a woody tan, and the pods begin to crack open. At harvest time, the plant looks like a bare, dry stalk lined with splitting capsules, which is when farmers traditionally cut and invert the stalks to catch the falling seeds.