How to Grow Cilantro

Cilantro looks a lot like flat-leaf parsley and is sometimes called Mexican parsley or Chinese parsley. Both cilantro and parsley are in the carrot family. A quick sniff of either plant is an easy way to tell the difference between the two.

Cilantro grows best in full sun, at least 6 hours each day, and moderately fertile, well-drained soil. This herb likes a soil in the 6 to 7 pH range.

It prefers cooler temperatures and will often bolt (send up flower stalks, flower, and begin making seeds) in hot, humid summers. When the plant bolts, the leaf quality and flavor diminish. If you leave the flower stalks, they will form seeds which can be harvested and dried for culinary use.

Cilantro can be started from either seeds or transplants. If you wish to start your own seeds, they can be sown indoors for an early start 4 to 6 weeks before transferring outside or you can plant seeds directly into the ground after the danger of frost has passed. Plant in early spring and in the early fall when the temperatures are cooler. When planting transplants in the fall, plant early enough to be able to harvest before frost.

If planting transplants, wait until after the danger of frost has passed to plant them outside.

This plant grows quickly, maturing in about 45 to 70 days, depending on cultivar.

Cilantro, like many other herbs, can be grown in containers. Rather than using a soil from your garden, use a potting mix formulated for vegetables and herbs. Potting mixes usually drain better and are less prone to compaction that may result when using garden soil in a container.

When planting either seeds or transplants, keep the ground evenly watered until seedlings and transplants are established. Do not let the soil dry out. Cilantro grown in outdoor containers may need to be watered more often.

After the plants are established, cilantro, which has a shallow root system, will benefit from being watered on a regular basis but will not need as much water. Cilantro does not like wet or saturated conditions.

Mulching around the plants helps keep the moisture levels even and the soil temperatures lower.

If you love using cilantro in culinary dishes, you may wish to plant a few plants at a time. For a continuous supply, sow seeds every two to three weeks to ensure a fresh supply of leaves for a longer period.

Because bolting can be an issue with this plant, consider cultivars that are slower to bolt. Among them: ‘Longstanding’, ‘Leisure’, ‘Calypso’, ‘Santo’, ‘Slow Bolt’ and ‘Cruiser’. When plants bolt and form seeds, leave the seeds until they ripen and turn brown.

Fertilizing

• When planted in fertile soil, cilantro may have all the nutrients it needs without a fertilizer application.  If you do apply fertilizer, apply sparingly. Texas A&M AgriLife Extension recommends fertilizing your plants with ½ teaspoon of ammonium nitrate (34-0-0) or urea (21-0-0) per square foot. Fertilize one to two times during the growing season.
• For herbs grown in containers, Minnesota Extension recommends a liquid fertilizer at half the label-recommended strength once every three to four weeks for herbs in containers outdoors and once every six weeks for herbs in containers indoors. Organic options are available at most garden centers. 

Controlling Pests, Diseases, and Other Problems

Cilantro does not have a lot of problems with insects and disease. Pests include aphids and cutworms. Aphids, commonly found on the undersides of the leaves, can be removed by spraying water on them. Cutworms can be handpicked off the plants.

Bacterial leaf spot looks like water-soaked spots with yellow edges that change to dark brown or black. It is best to remove and destroy the plant. Do not compost it. 

The best way to prevent problems is to employ good cultural practices:

• Start with healthy, disease-free plants
• Plant in good, healthy soil and keep it evenly moist 
• Keep the foliage dry by watering at the base of the plant and not overhead
• Give your plants room to grow and to have good air circulation 

From seed, cilantro is ready to harvest after 45 to 70 days, depending on cultivar. Harvest when the plants are about 6-inches tall. Harvest the top, which forces it to branch and grow more thickly. Small leaf branches can be harvested through the season. Harvest no more than a third of the plant at a time.

The best time of day to harvest cilantro and other herbs is mid-morning when the dew has dried and before the heat of the day is hottest.

When growing cilantro for the seeds, allow the plants to flower. When the flower heads turn brown, harvest the seeds in mid-summer. Roll the brown seed pods in your hand to remove the outside hull. The coriander seeds can be crushed, and used in various dishes.

Storing

Cilantro can be stored in the refrigerator for a few days. One way is to strip lower leaves from the stem and place a bunch of cilantro in a glass or jar of water. Or they can be wrapped loosely in a moistened paper towel and stored in the refrigerator.

This is a delicate herb, which can make it difficult to dry, but bundling a few pieces and hanging upside down until the leaves dry is a method for preserving. Hang cilantro or other herb bundles in a dry, protected, shady location. Another method is to use a dehydrator. When dry, strip the leaves off the stems and store in an airtight container. 

Freezing leaves for later use is yet another way to extend the use of home-grown goodness. Chop or puree leaves into small pieces, mix with water or olive oil, freeze in ice cube trays. When frozen, remove the cubes from the trays and store in the freezer in freezer bags. It is easy to remove a cube or two to flavor soups, sauces, and other dishes. 

• The better your soil, the better your chances for healthy plants. 
• Succession planting, every 2 to 3 weeks, is a great way to enjoy this herb for a longer period.