When to Plant Cilantro

The rule behind cilantro timing

Cilantro is grown for its leaves, and it stops making good leaves once it flowers. Two things push it to flower: warm temperatures and long days. Oregon State University’s vegetable breeders describe the difference plainly: plants growing in the cool, short days of spring or fall produce leaves for several weeks or months, while midsummer plantings bolt and set seed within 4 to 6 weeks. Every planting date for cilantro is an attempt to give it as many cool, short-day weeks as possible.

Soil temperature also favors the shoulder seasons. Oregon State gives 55 to 68°F as the germination range, and Utah State says seed takes about 3 weeks to come up. A sowing made in early spring or late summer germinates in that window and then grows through cooling or still-mild weather.

Spring planting

The dates for your zone above cover the spring window. Extension services differ on how early to start. UW-Madison Extension says to sow in early spring, when lettuce is sown. Illinois Extension and Utah State University recommend sowing after the danger of frost has passed. The earlier date buys more cool weeks before summer; the later one avoids the risk of a hard freeze. Utah State notes that cilantro can also be started indoors 4 to 6 weeks before setting it out after frost, but its taproot makes it a poor transplant, so most gardeners sow directly.

Oregon State suggests continuing to sow from early spring through early summer. Each later sowing runs into warmer, longer days sooner, which is why Oregon State recommends a cool or semi-shaded spot for leaf crops as the season warms.

Fall planting

Fall is often the better season, because plants mature into shortening days and falling temperatures instead of rising ones. UW-Madison recommends sowing a fall leaf crop in mid-August in Wisconsin, and Utah State says successive plantings can continue until late summer. Oregon State’s schedule for the Pacific Northwest resumes in early autumn.

Light frost is not a reason to stop. Oregon State says mature plants tolerate light freezing, though UW-Madison warns cilantro will not survive a hard freeze. Cover fall plantings on nights when a hard freeze is forecast.

Warm-winter areas and the South

In zones 9 and 10, cilantro is a fall-to-spring herb, and summer sowings bolt almost at once.

• Florida: UF/IFAS says fall and winter are best and suggests sowing every 2 to 3 weeks through fall, winter and spring. The UF/IFAS Osceola County herb calendar for Central Florida marks September through March.
• Gulf Coast of Texas: the Galveston County AgriLife office names October as a good time to plant cilantro.
• Low desert: University of Arizona Extension in Tucson recommends October to November and February to April, with frost protection on cold nights. The Yuma County calendar runs from September to December, but advises most gardeners to wait until October unless they can shade and water seedlings through the last hot days.
• California’s Central Valley: UC Cooperative Extension Sacramento says to grow cilantro in spring or fall because it does not tolerate summer heat.
• Warmer parts of Utah and similar mild-winter areas: Utah State says fall-sown seed gives a spring harvest.

Succession sowing

A single sowing gives only a few weeks of leaves, so sow small amounts on a schedule: every 2 to 3 weeks according to UW-Madison, or every 3 to 4 weeks according to Illinois. Stop when summer heat arrives, then start again in late summer.

If you plant in summer anyway

Summer sowings are not wasted if you want something other than leaves. UW-Madison notes that the flowers feed beneficial insects and pollinators, and a seed crop for coriander needs at least 100 days, and Utah State says seed forms in late summer or early fall on plants left to flower.