Cilantro (Coriandrum sativum)
This annual herb is known officially as coriander just about everywhere outside of the Americas. We often think of the fresh leaves as cilantro, and the seeds (which are very easy to harvest) as coriander. Cilantro is the Spanish name for coriander. The plant is native to North Africa and Mediterranean Europe, and is a member of the carrot family, Apiaceae. Its close relatives include parsley, fennel, and dill, which is easy to see when the plant flowers, producing tall umbels of white flowers. Each cilantro “seed” is actually a schizocarp that can be divided into two one-seeded segments. These split seeds are known in the seed trade as monogerm. These are handy for growers who need to do very precise seeding.
Cilantro plants are famously prone to bolting. That is, they go to seed, sending up a rapidly growing flower stalk, when the plants are stressed. Growers expect this to happen once the soil warms up in the summer, but many cultivars have been bred to resist bolting, such as Santo Long Standing. This variety will still “run to seed” in hot weather, but days later than others. As the flower stalk grows, the leaves along its length become feathery, alternating asymmetrically up the stalk.
Cilantro flower clusters open in a formation known as an umbel. The umbel of tiny flowers is highly attractive to beneficial predatory insects such as hover-flies. These insects are first attracted to the flowers, but will then feed on pest insects like aphids, thrips, and small caterpillars, so once cilantro starts to bolt - let it!
Quite a lot is known about cilantro in history. Cilantro is thought to have been cultivated in ancient Egypt, as it was another spice present in the tomb of Tutankhamun, but does not grow wild there. It is mentioned in the Bible (Exodus 16:31), and it has been unearthed in archaeological digs from Bronze Age Macedonia. It was introduced very early to North America via the English colonies in the 17th century, and may have been one of the first crops planted there.
Cilantro has a unique, sharp, almost citrus taste that some people consider soapy and unpalatable. Studies have revealed that 80% of identical twins share either a strong preference for, or aversion to, the herb. Meanwhile, among fraternal twins, the preference/aversion is shared only around half the time. Evidence is strong that aversion to cilantro is genetic, and that it’s chemically hardwired into the brain. Those who don’t care for the herb cannot, apparently, come around to liking it.
The herb is used around the globe in masses of diverse cuisines, and flavours some of the world’s tastiest dishes. It is a pan-cultural ingredient, and may be one of the most commonly used spice plants. All parts of the plant can be used, from the roots to the seeds, although the seeds have a distinct taste all their own. Ground coriander seeds are an essential element of curry powder, and countless masalas, or spice mixes. The flavour of coriander seeds is enhanced once they have been toasted in a dry pan.
The flavour in the leaves of cilantro dissipates quickly when heated, a bit like basil, so it is often added at the end of cooking, or as a garnish to add complexity to a dish. The stems can be used in stocks, and provide a nice background to the lime and fish sauce of Southeast Asian soups and sauces. The roots can be washed and chopped or pulverized into Coriander Root Paste that complements coconut very well and is delicious on anything grilled over flame. Cilantro is high in vitamins C and A.
How to Grow Cilantro:
Difficulty: Easy. Cilantro works well in containers over 15cm (6”) deep.
Timing: Direct sow from early March to around the third week in September. Cilantro is a cool-loving plant, and will bolt in warm weather, so grow it in the spring, and then in the fall/winter under a cloche. In summer it can be grown, but you need to stay on top of it, or simply allow it to flower and harvest the seeds.
Sowing: Sow seeds 1cm (½”) deep, about 8cm (5”) apart in rows 15cm (6”) apart.
Soil: Grow in full sun or bright shade, in rich, well-drained soil. Cilantro develops a tap root like a short, white carrot, so it requires deep soil to prosper. Aim for a pH of 6.0 to 7.5.
Growing: Keep well-watered. Feeding is not necessary if there is sufficient organic matter in the soil.
Harvest: Wait until the plants have formed small bunches of dark green leaves before picking as needed. Otherwise, harvest as whole bunches. To harvest the leaves, allow the plant to flower, and then wait for a number of days until the seed heads begin to dry. These can be shaken into paper bags for later cleaning and storage. NOTE: cilantro seeds need to be kept out of the compost, as it will appear like a weed in following seasons.
Storage: Cilantro leaves and stems do not dry or freeze well. Use fresh whenever possible. It will hold in the refrigerator crisper for about 5 days. The seeds should be allowed to dry thoroughly, and then can be stored in the spice cupboard in a sealed glass or plastic container. These can then be ground (sometimes roasted first), as needed for curry powders and other spice blends. The roots of cilantro can be hard to find in winter here in North America, so cut some from their stems, rinse them and dry them well, and then freeze them in foil for later use.
Seed info: There is no government standard for cilantro germination, but it will remain high for up to 5 years.
Growing for seed: Some bolt-resistant varieties are available. If growing for seed, isolate individual varieties by 1km (½ mile) for best results. The plants are insect pollinated, but will not cross with other vegetables or herbs.
Pests & Disease: Unlikely. If left to bloom, cilantro will attract hoverflies and predatory wasps. The USDA has conducted trials in the Salinas Valley of California that show cilantro flowers being effective controls for aphids. Cilantro and insect-attracting Alyssum were inter-planted with lettuce crops, producing a significant decrease in damage from aphids. The larvae of the hoverflies they attract each eat up to 150 aphids per day. More on Companion Planting with Umbelifers.
