Coriander, known as cilantro in its leafy form, is a popular herb in many global cuisines. This annual plant offers a dual harvest: its vibrant green leaves are used as a fresh herb, while its dried seeds serve as a spice. Understanding its life cycle helps cultivators maximize yield, whether for a continuous supply of leaves or a bountiful harvest of seeds.
Coriander Seedling Stage
Coriander’s life cycle begins with seed germination, typically taking 7 to 21 days. Seeds benefit from consistent moisture and soil temperatures of 15°C to 25°C (59°F to 77°F). Some gardeners gently crush seeds before planting to improve germination rates by splitting them. Coriander seeds do not require light for germination and may germinate better in darkness.
Once germinated, a tiny root emerges, anchoring the seedling. Soon after, two small, oval cotyledons (seed leaves) unfurl above the soil, providing initial nourishment. These are followed by the first true leaves, distinctly different from cotyledons and familiar as cilantro’s flat, lobed leaves. During this phase, young seedlings require protection from pests and harsh weather, along with consistent moisture for establishment.
Coriander Vegetative Growth
Following the seedling stage, coriander enters vigorous vegetative growth, producing green foliage. During this phase, the plant develops more true leaves, and its stems branch, increasing its size and bushiness. This is the ideal time for harvesting the aromatic leaves, often called cilantro.
For robust leaf production, coriander thrives with at least 4-6 hours of direct sunlight daily, benefiting from partial shade in hot climates to prevent premature bolting. The soil should remain evenly moist but not waterlogged, as both dryness and excessive wetness stress the plant. Fertilizing with a balanced or high-nitrogen feed every few weeks supports continuous leaf development, as nitrogen promotes foliage growth. Regular harvesting of outer leaves also encourages new growth from the center, prolonging the leafy stage.
Coriander Bolting and Flowering
As environmental conditions shift, coriander transitions from vegetative to reproductive growth, known as “bolting.” This often occurs when temperatures rise, exceeding 24°C (75°F), or when daylight hours lengthen. Stress, such as insufficient water or nutrients, can also trigger bolting. The plant responds to these changes by completing its life cycle and producing seeds.
Visual cues of bolting include a tall, rigid central stalk, and previously broad leaves becoming feathery and sparse. Small, delicate white to pale pink flowers emerge in clusters at the top of these stalks. Bolting is undesirable for leaf production because leaves develop a bitter flavor once the plant flowers. To continue harvesting leaves, removing flower stalks can temporarily delay this process, but the plant will inevitably shift focus to seed production.
Coriander Seed Production
After flowering, the coriander plant dedicates energy to seed development. Small flowers transform into green, spherical seed pods. These immature seeds are initially soft with a distinct, sharp flavor. Over several weeks, seeds mature, drying out and changing color from green to pinkish-brown, eventually becoming hard and brown. This transformation signals they are ready for harvest.
Harvesting coriander seeds typically occurs around 120 days (four months) after planting. When most seeds have turned brown and are easily detached, the entire plant can be cut at the base. To complete drying, harvested stalks with seed heads can be hung upside down in a brown paper bag or spread in a dry, well-ventilated area for one to two weeks. Once thoroughly dry, seeds will readily fall off. Properly dried coriander seeds should be stored in an airtight container in a cool, dark, dry place, maintaining flavor and viability for up to three years.