Cilantro, Coriandrum sativum, (also known as coriander or Chinese parsley) is one of those plants with intensely pungent, aromatic leaves that one either loves or loathes. The seed, more usually called coriander, is one of the oldest known herbs. This versatile herb is grown as a hardy annual and produces both leaf and seed used in cooking. When dried, the seeds have a sweet, lemony flavor after they age. The leaves can be used fresh or frozen for later use.
When growing cilantro In cold weather areas, it is best to grow the herb from seed, planted indoors 3 to 4 weeks before the last frost, then transplant outdoors in spring. When planting the seed, you can use peat pots, one seed per pot, to then be planted directly outdoors in the ground pot and all. Some gardeners have direct seeded Coriandrum outdoors in the fall for a spring crop, but this technique is most successful in zones milder than the NYC metropolitan area. In cold weather areas like ours, seeds formed in summer, fallen or planted, may germinate the following spring if winter is unseasonably mild.
To start the herb indoors, first soak the seeds for 24 to 48 hours and dry them before planting in their individual peat pot, ¼” deep. The seeds will need a temperature of 60 degrees F. to germinate, taking 7 to 10 day. Young plants like cool temperatures to grow well, about 55 degrees F. outdoors. Transplant into compost-amended soil in spring after danger of frost has passed and the seedlings are 2 to 3 inches tall. Plants prefer loamy, well-drained soil in full sun, spaced 6 to 8 inches apart. Water regularly but take care; plants do not like overly wet or humid growing conditions. (Note: cilantro is not a good garden companion for fennel, hindering fennel’s seed formation. It does, however, enhance the formation of anise seed and so makes a good companion plant with anise.)
Once the plant grows tall, you can cut about ¼ of the foliage at a time. Harvesting it regularly is fine, but cutting over ⅓ of the plant may cause it to grow poorly. Pinch back young cilantro plants an inch or so to encourage fuller, bushier plants. To delay seed production, snip off the top part of the main stem as soon as it appears to be developing flower buds or seedpods. Cutting off the flower heads redirects the cilantro plants’ energy back into leaf, and not flower or seed production. The plant will grow to a height of 2 to 3 feet.
When the weather gets warmer, cilantro will send up tall shoots, with umbels of pink or white flowers, signaling their harvest season has come to a close. This bolting can be accompanied by a bitter taste to the remaining foliage. Shortly after flowering, the seed (coriander) will be produced (at about 90 to 105 days after sowing) and may be used in cooking and baking. To avoid excessive loss of seed during harvest, collect seeds when about half have changed to a light brown color.
For a fall crop, you can start seeds again in late summer and, once planted out, the seedlings will once again enjoy the cooler garden temperatures in which it flourishes.
Cilantro also makes a useful container plant, kept in a sunny spot near the door for easy use in the kitchen. Choose a relatively shallow but wide, round, container and fill it with moistened, potting soil mixed lightly with a slow release fertilizer. Sow the seeds thickly and cover with a light coating of soil. As in the garden, cilantro will mature quickly to seed production but you can extend its life by harvesting the leaves continually so that it doesn't reach this stage. As soon as the first leaves appear, snip from one section for use in your kitchen. Harvest frequently, each time moving slightly around your circular container until you are back to the start where new growth will have sprouted up.
If your primary interest is leaf production (cilantro), choose a variety that is slow to bolt, such as 'Long Standing', 'Slobolt', "Calypso' or 'Leisure'. For seed production (coriander) or both leaf and seed, most varieties will do equally well.
Traditionally used for Mexican dishes, fresh cut and gently washed cilantro leaves with fine stems can be chopped and sprinkled over entrees or used in Indian and Asian cuisines for curries and salads. Cilantro should be used as fresh as can be found, as it does not keep longer than one or two days. You can tell how fresh cut cilantro is by the strong scent and bright green color. You can actually preserve it by freezing it in olive oil. To do this you will need an electric blender, spatula and ice cube tray.
First rinse fresh cilantro well in a bowl by holding the stems, swishing the leaves in the water and draining it in a colander. Pat dry with paper toweling. Roughly chop the leaves along with the stems. To make a puree, use ⅓ cup extra virgin olive oil to one packed cup of chopped cilantro. Place these ingredients in a blender and pulse a few moments, stopping to use a spatula to scrape down the sides. Pulse a little more to make the puree. The olive oil will help to preserve the bright green color of the cilantro. Spoon puree into the ice cube tray and freeze. After a few hours, once the cubes freeze, put them in a labeled freezer bag (individual cubes are easily removed for use). You will be surprised how fast the flavorful, green cubes melt when added to hot soups or stews. No oil, no problem; you can freeze a thin layer of fresh cilantro in a freezer bag. Once frozen, open the bag and break off what you need. Enjoy cilantro anytime of the year!
The seeds are used as an aromatic spice in a great many foods from stews to cakes and breads. They should be dried but are best used within six months after harvest.
A simple technique for preserving as many seeds as possible during the harvest is to snip the entire seed head into a paper bag. Label bags with seed type and date of harvest and keep the bag in a dry place in the house until the seeds fall to the bottom. Then sort seeds from other plant material and spread the seeds on newspaper to dry completely from one to two weeks. Seeds need moisture, warmth and light to germinate, so give them the exact opposite, a dry, cool, dark environment, when storing them for later use. Place your seeds in an envelope and seal them in plastic containers or glass jars. If you are not convinced that your seeds are dry, eliminate the airtight container step. Alternatively, infuse the dried seeds to create a coriander vinegar.
Cilantro is a short-lived plant and will have a limited life of up to eight weeks indoors. It is not always easy to grow in the home because it needs a minimum of 6 hours of strong, direct, daily sunlight and only thrives at temperatures below 70 degrees F. (Above 75 degrees it will go quickly to seed.) In the summer, it will need to be moved from the hot sun in the afternoon. In winter, it may be placed under a growing lamp for 12 to 16 hours a day for adequate light.
Water the plant thoroughly and allow the soil to dry before watering again. Do not let your cilantro plant sit in water or excessive humidity. Turn the plant every few days as it will grow toward the sun. Feed with a general purpose fertilizer every two to three weeks.
Coriander seed, which is indigenous to Southern Europe and the Mediterranean region, was cultivated in ancient Egypt for culinary and medicinal use and is mentioned in Sanskrit texts. The leaves are not widely used in Europe, except for Portugal, by way of Africa. Cilantro leaves are more widely used in Latin America and Southeast Asia, with fish and seafood, meat and poultry, in salads and soups, often as a lavish garnish. In the Middle East, fresh cilantro is so widely used that is called ‘Arab parsley’. Both seed and leaves are used extensively in India. The seeds are in garam masala and occur in many curry-type dishes, as do the leaves. The roots (sometimes seen at groceries) are used by cooks in Thailand, added to curry-type dishes, as in India.