Cilantro is a delicious herb to eat but a fickle plant to grow. Also known as coriander or Chinese parsley, cilantro (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 individual cilantro plant to live only for a few months before it flowers.
- Botanical Name: Coriandrum sativum
- Common Name: Cilantro, coriander, Chinese parsley
- Plant Type: Annual herb
- Mature Size: 20 inches tall
- Sun Exposure: Part sun, indirect sun
- Soil Type: Loamy
- Soil pH: 6.5 to 7.5
- Bloom Time: Spring
- Flower Color: White, pale pink
- Hardiness Zones: 3 to 11
- Native Area: Southern Europe, Northern Africa, Southwestern Asia
How to Grow Cilantro
Cilantro an annual herb and does not easily root from cuttings, but it readily produces seeds and self-seeds. Therefore, it's best to grow cilantro from seeds rather than transplanting it. If you allow your plant to mature, you can harvest the seeds for next season. Because it's a short-lived plant, if you want a steady supply of cilantro, sow seeds every few weeks to keep a fresh supply of young plants.
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.
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 a 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 a garden soil, which is too heavy.
Plant the cilantro seeds between 12 and 18 inches apart in the fall in zones 8 and higher or in the spring about a month before the last frost in the lower zones.
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. Keep your plants around 70 degrees F to you'll extend the harvest time. Once cilantro bolts, the flavor changes. Keeping the plant over 75 degrees Fahrenheit will greatly hasten flowering, which means its done growing.
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 24 inches tall, including flower stalks.
Varieties of Cilantro
- Calypso: Full plants that are slowest to bolt
- Cruiser: Large leaves and full stems with an upright plant habit
- Leisure: Standard type of cilantro that attracts beneficial insects
- Santa: Slow-bolting plant with bushy leaves
As the plant grows, pinch back the cilantro about an 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.
From the time of sowing seed, cilantro leaves can begin to be harvested in about three to four weeks. Cilantro seeds 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, known as coriander, clip the seed heads and put them upside down in a paper bag. Give it a couple days, and the husks will dry, split, and drop out the seed that's inside.
Common Pests and Diseases
Cilantro can suffer from some common diseases and pests, though both can be managed easily. Diseases that regularly affect cilantro include bacterial leaf spot, soft rot, carrot motley dwarf, damping-off, and powdery mildew. You can tamper the possibility of disease by avoiding overhead irrigation and not working with the plant while it's wet.
Pests to watch out for include aphids, including willow-carrot aphid, armyworm, cutworms, and root knot nematode. If infestations are minor, prune out the pests. Otherwise, turn to additional management tactics, such as solarizing the soil to reduce nematodes or applying the appropriate insecticides to the infested areas.