Cilantro, a Unique Culinary Herb
Cilantro, Coriandrum sativum, is an herb that you either love or hate. It has been described as one of the "most polarizing and divisive food ingredients known." The taste of cilantro appears to be experienced differently among people. The lovers of cilantro have described it as fresh, citrusy, and fragrant; whereas the haters of the herb describe its taste as soapy and reminiscent of bugs. Because of its increased popularity and the fresh, plant-based diet trend, there have been studies on why some dislike cilantro so much.
Researchers conducted a study with over 14,000 participants of European descent who described cilantro as soapy tasting. They also looked at genetic variations in an additional 11,000-plus participants who stated whether or not they liked cilantro. They found a gene called OR6A2 that enables people to detect the smells of chemicals like E-(2)-decenal which is a primary constituent of cilantro and also happens to be found in the defensive secretions of stink bugs! Now you know why you may dislike cilantro. But what about those who love cilantro? Well, there may be a genetic mutation that inhibits them from smelling that compound.
Despite people's love/hate relationship with cilantro, it is one of the oldest herbs in use—over  3,000 years—which was documented in the Ebers Papyrus (an Egyptian medical papyrus) from 1550 BCE. This annual plant originates from the eastern Mediterranean region. All aerial parts of the herb are edible. And it is noted that the leaves and stems, known as cilantro, have distinct culinary uses that differ from the seeds, known as coriander. Cilantro is a preferred ingredient in Mexican and Asian cuisine. The fresh leaves, and oftentimes the tender stems, are favored—since cooking or drying diminishes their flavor. Once the plants have reached 6 inches in height, harvesting can begin by cutting one-third of the plant at ground level each time. Clean and pat dry, wrap loosely in plastic, and refrigerate for up to one week.
Many cilantro lovers struggle with growing cilantro, for it is finicky. Cilantro thrives in cool climates, especially during the spring and fall. The first sign of hot temperatures, and the cilantro is quick to flower and set seed—this growth response is called bolting. This results in bitter-tasting leaves. However, you should have no fear, for there are options that will allow you to extend your cilantro season.
First, you want to ensure that you have the ideal growing conditions for your cilantro. That means full sun and well-drained soil with a pH around 6.5, which is what most herbs and vegetables require. Keeping the cilantro watered and mulched with straw will help keep soil temperatures cool. Site your cilantro where there is some afternoon shade to extend its lifespan when temperatures heat up.
Eventually, the cilantro plants will find conditions too scorching for their liking and they will set seed. And let them. This self-sowing process may bring about seedlings when things cool down. You can also do this yourself through the process of successional planting. Sow seeds every two to four weeks through the season for a continuous supply of the herb. For healthier and stronger plants direct sow the seeds 6 to 8 inches apart, rather than transplanting them. Or you can find several varieties that are slow to bolt. Popular slow bolting cultivars include: 'Slow Bolt,' easy to grow and takes 50 days to mature for leaf harvest; 'Leisure,' heat tolerant, high yielding, and ready to harvest in 28 to 40 days; 'Santo,' a darker leaf color, but good, uniform flavor; and 'Calypso,' the slowest to bolt of the varieties, three weeks slower than 'Santo' with a bulky, full habit. A new, fun cultivar is 'Confetti,' a fern-like cilantro that is used for baby-leaf production, beneficial for garnishes, and requires less chopping.
Cilantro suffers from a few pests and diseases. Pests include aphids, cutworms, and armyworms. Aphids are the most common and usually found on the underside of leaves and along the stems. A good hard spray of water is an easy control method. If the cilantro seedlings are suddenly eaten off, that is a good indication of cutworms, which are white- to cream-colored caterpillars. And if leaves become skeletonized, that is the work of armyworms, which are green and striped caterpillars. Hand-picking is the typical mechanical control method for both of these caterpillars. Of course, planting cilantro in an area with other herbs and even pollinator plants will encourage beneficial predatory insects and be a most welcome biological control in the garden.
Of the diseases that can affect cilantro, bacterial leaf spot is the most frequent culprit. Signs begin with water-soaked spots with a yellowish edge. These slowly enlarge and become dark brown/black and will also have a reddish center. Remove infected plants immediately, but do not compost—since diseases can often thrive in the compost's moist conditions. Increase air circulation and water at ground level, not overhead. For the next year's planting, rotate your crop and plant cilantro where another plant family, not Apiaceae, was located. (Apiaceae examples include parsley, celery, chervil, and dill.)
Overall, cilantro is a unique but polarizing herb. Having increased in popularity over the past decade, it will surely continue the trend in years to come.
Resources
A genetic variant near olfactory receptor genes influences cilantro preference
