Cilantro, known botanically as Coriandrum sativum, is a distinctively flavored annual herb whose fresh leaves are a staple in global cuisine. While it is often considered a challenge for home gardeners due to its tendency to prematurely flower, a successful harvest is achievable with the right techniques. The key to a lush, continuous supply of cilantro lies in understanding and controlling the plant’s environmental preferences from the moment the seed is sown. This guide provides the practical steps necessary for planting cilantro seeds and ensuring a bountiful yield.
Site Selection and Timing
Successful growth begins with choosing the right location and planting window. As a cool-season crop, cilantro thrives when temperatures are consistently between 50°F and 85°F. Plant in early spring, as soon as the threat of hard frost has passed, or in late summer and fall for a second harvest. This timing avoids the intense heat of mid-summer, which triggers the plant’s life cycle to end.
The planting site should receive full sun, but afternoon shade is beneficial in warmer climates to prevent stress. Cilantro requires rich, well-draining soil to support its taproot. Amending the area with organic matter, such as aged compost, improves fertility and drainage. The soil should maintain a slightly acidic to neutral pH level, ideally between 6.2 and 6.8.
Sowing the Seeds
Proper seed preparation improves germination speed and consistency. The cilantro “seed” is actually a fruit capsule containing two separate seeds encased in a hard husk. Gently crushing this husk, often with the back of a spoon, exposes the inner seeds and accelerates water absorption.
To further accelerate germination, soak the separated seeds in water for 24 to 48 hours before planting to soften the seed coat. Sow the prepared seeds directly into the garden bed, as cilantro develops a long taproot that dislikes being disturbed by transplanting. Plant the seeds shallowly, covering them with approximately one-quarter to one-half inch of fine soil.
For continuous leaf harvesting, sow the seeds closely, spacing them about one to two inches apart in rows spaced 12 to 15 inches apart. After sowing, gently water the planting area with a fine spray to avoid displacing the seeds. The soil should be thoroughly soaked to ensure good seed-to-soil contact.
Care During Germination
The period immediately following planting is critical for successful seedling establishment. Cilantro seeds typically germinate within 7 to 10 days, though cooler soil temperatures can extend this period to two or three weeks. Throughout this phase, maintain consistent moisture.
The soil should be kept evenly damp, but never waterlogged, as excessive moisture can lead to fungal issues and seed rot. Once seedlings emerge and reach two to three inches in height, thin them to give remaining plants adequate space. Space the remaining plants between two and four inches apart; this promotes air circulation and prevents overcrowding.
Maintaining Growth and Harvesting
The primary challenge in growing cilantro is preventing bolting, the premature transition to flowering and seed production that makes the leaves bitter. Bolting is triggered by soil temperatures rising above 75°F and the longer daylight hours of summer. Providing afternoon shade, such as with a shade cloth or by planting near taller crops, is an effective strategy to keep the environment cool.
Consistent moisture management is another defense against bolting, as water stress signals the plant to accelerate its life cycle. Cilantro does not require heavy fertilization; incorporating compost before planting usually provides sufficient nutrients. If growth seems sluggish, apply a light application of a balanced, organic liquid fertilizer after several harvests.
To maximize the harvest, employ the “cut-and-come-again” method, which encourages new foliage production. Harvest the outer, more mature stems and leaves, cutting them at the base near the soil line. Take care to leave the central growth point untouched. Avoid removing more than one-third of the plant’s foliage at any single harvest to ensure continued production.