Coriandrum sativum is known as either coriander or cilantro, but whatever it is called, it is a delicious herb to eat but a fickle plant to grow. Coriandrum sativum can be grown outside in a garden, but it also does well when grown in containers. No matter which way you grow it, though, once it sprouts, the race is on to harvest leaves before the plant flowers and the flavor profile changes. Expect your cilantro plant to live only for a couple of months before it flowers, at which point it becomes useless as a culinary plant.
Cilantro is a fast-growing but short-lived plant that is ready to harvest in just three or four weeks, so you can start planting it in the early spring, just after the last expected frost. You may also want to replant in early fall for a fall harvest. It won't do well in the heat of summer, however.
|Botanical Name||Coriandrum sativum|
|Common Name||Cilantro, coriander|
|Plant Type||Annual herb|
|Mature Size||18–24 in. tall, 12–18 in. wide|
|Sun Exposure||Part sun, filtered sun|
|Soil Type||Loamy, well-drained|
|Flower Color||White, pale pink|
|Hardiness Zones||3 to 11 (USDA)|
|Native Area||Southern Europe, Northern Africa, Southwestern Asia|
Coriandrum sativum is known as either coriander or cilantro, depending on circumstances. In North America, it is standard to know the leaves and stems of this plant as cilantro, while the seeds are known as coriander. In other parts of the world, however, the leaves and stalks are known as coriander, while the seeds are known as dried coriander.
Cilantro can be grown from nursery transplants, but it is also a very easy plant to grow from seeds sown directly in the garden. Plant the seeds about 2 inches apart in rows spaced about 12 inches apart. If planting in pots, use an ordinary potting mix. Keep the soil moist as the seeds germinate and sprout. Thin the seedlings to about 6 inches apart, and keep them consistently moist as they grow.
Cilantro will readily self-seed, and you will likely find that a patch of cilantro reliably produces volunteer plants for as long as you want. You can either harvest the seeds by hand and save them for replanting, or simply allow them to drop seeds in the garden and allow them to sprout up randomly.
Cilantro likes bright indirect light but dislikes intense, direct sunlight. The best option for container gardens is morning sun in an east-facing window or a very bright sill that doesn't get too much direct sun. In the garden, they will do best in a spot with afternoon shade.
Cilantro does best in airy, light, fast-draining soil with plenty of perlite or sharp sand mixed in to increase drainage. If the cilantro is in the garden, add mulch around the plants as soon as they've grown enough to be visible. In a container, use a premium potting mix rather than garden soil, which is too heavy.
Keep the soil regularly moist, but not soaked. Good drainage is essential, as cilantro has deep roots. Aim for about 1 inch of water per week.
Temperature and Humidity
Cilantro bolts easily, especially in warm weather. In the garden, flowering will occur quickly once the temperatures exceed 75 degrees Fahrenheit. Once cilantro bolts, the flavor changes, often becoming bitter. With potted plants, you can extend the harvest season by keeping the plants around 70 degrees—bringing them indoors to an air-conditioned environment when outdoor temperatures get warm.
- 'Calypso': This cultivar produces very full plants that are among the slowest to bolt.
- 'Cruiser': The variety has large leaves and full stems with an upright growing habit.
- 'Leisure': This is a very standard type of cilantro that attracts beneficial insects.
- 'Santa': This variety is another slow-bolting plant with bushy leaves.
- 'Confetti': This is a highly ornamental variety, with fine, fern-like leaves.
As the young plants grow, periodically pinch back them by about 1 inch to encourage fuller plants. To extend your cilantro harvest, regularly snip soft stems, rotating the plant as you harvest to encompass the whole plant.
Potting and Repotting
Cilantro is an annual that grows with a deep taproot. As a result, it dislikes repotting and will often bolt at the slightest provocation. It's best to repot your garden-center cilantro only once after bringing it home, then keep the plant in that container for the rest of its life.
Seed-grown cilantro can transition from your seed-starting pot to its permanent home pot. Because cilantro is an annual, mature plants should never need repotting. A fully mature flowering cilantro plant can hit a height of 24 inches, including flower stalks.
How to Harvest Cilantro
From the time you sow the seeds, cilantro leaves will be ready to harvest in just three to four weeks. Cilantro seeds (coriander) can be harvested in about 45 days, or when the plant is 3 to 4 inches tall. Cut the leaves at the bottom of the plant, if possible, and avoid harvesting more than one-third of the plant at the time. Cutting off too much can weaken the plant.
If you're harvesting the seeds, clip the seed heads and put them upside down in a paper bag. Give it a couple of days, and the husks will dry, split, and drop out the seeds inside.
Common Pests & Diseases
Cilantro can suffer from several common garden pests and diseases, which are generally managed easily. Pests to watch out for include aphids, armyworms, cutworms, and root-knot nematodes. If infestations are minor, prune out portions damaged by pests. Otherwise, turn to additional management tactics, such as solarizing the soil to reduce nematodes or applying the appropriate insecticides to the infested areas.
Diseases that regularly affect cilantro include bacterial leaf spot, soft rot, carrot motley dwarf, damping-off, and powdery mildew. You can reduce the possibility of disease by avoiding overhead irrigation and not working with the plant while it's wet.