First many people wonder what the difference between cilantro and coriander are. Actually they come from the same plant. Cilantro generally describes the leaves of the Coriandrum sativum plant, while coriander is the dried seeds of the cilantro. Cilantro is in the parsley family therefore many people confuse the two. Cilantro is becoming more and more popular in recipes today, largely due to the use of it in many Mexican recipes. The strong distinct flavor and smell of cilantro have made it a very popular herb to grow in the vegetable garden.
Cilantro can be started from seed either indoors or outdoors directly in the soil. Seeds should be sown ½ inch deep and about five inches apart. It is a good practice not to plant all your seeds at the same time so you can harvest your cilantro over an extended period of time. This is because you must pick your leaves before they begin to flower and turn to seed. Ideally cilantro likes morning sun and a bit of afternoon shade, so if you have a space in your garden that fits this description use this area. Plants should be started after the danger of frost has passed. However don’t wait too long to plant your seeds as the hotter it gets the more likely your plants will bolt and turn to seed. Cilantro generally prefers a soil pH range of 6.1 to 7.5. If you don’t know the pH of your soil there are inexpensive kits that can help you.
Pick the cilantro leaves off your plant as needed for your use. If the plants do begin to flower, it is best to cut off the flowers. This will allow a little more leaf growth, as the energy of the plant isn’t directly towards the flowers. Cilantro will generally be ready to harvest about 60 days after you sow the seeds. It is best to trim the outer leaves first, thus allowing the smaller leaves to continue growing. It is best to use cilantro fresh, as the leaves will dry out and the flavor will begin to disappear.
If your goal is coriander, then you should let your plants flower and go to seed. Keep in mind that cilantro will bolt, which is sending up a flower stalk, when the roots of the plant reach 75 degrees or more. Therefore if you want coriander you should keep your plants in a shallow pot, where the soil can heat up quickly. However if you want cilantro, you should not use a shallow pot, as the soil warms too quickly. Keep this in mind if you are buying cilantro seedlings from a garden center or nursery, as these plants may already have soil temperatures of around 75F.