Days to germination: 10 to 16 days
Days to harvest: 40 days for cilantro, 90 days for coriander seeds
Light requirements: Full sun
Water requirements: Regularly
Soil: Loose and well-drained
Container: Needs a tall pot, but is well-suited otherwise
There may be two names in the title, but this article is about growing just one plant. Coriander is the actual name of the plant, and also the name given to its aromatic seeds. When the leaves of the plant are used, the herb is cilantro. So they are two different herbs but the same single plant.
Coriander seeds have a very spicy lemon flavor and are used in many Indian and Mediterranean dishes. Cilantro also has a citrus taste but is distinctly different from the taste of the seeds.
The plant is an annual that can grow up to 2 feet tall. It can be a finicky plant when it comes to care and watering, so expect to be patient and attentive to your coriander if you want to good crop of herbs.
Cilantro leaves have vitamins A and C, calcium and potassium but the seeds do not. They are not overly nutritious in their own right but do have some fiber and a small amount of manganese.
Starting from Seed
Coriander roots are quite sensitive and they do not take to transplanting very well. It’s advisable that you just sow your seed where you want your plants, directly outdoors.
Wait until all risk of frost has passed by at least a week before putting out coriander seeds. If you use a lot of coriander, you can put more seeds out a few weeks later to get a staggered harvest later in the season.
Your seeds should be about half an inch under the soil, and spaced 12 inches apart. Or you can sow them closer and thin them out later as they begin to grow. The small plants can be used though they will be quite a bit milder than mature cilantro.
Grow your coriander in a sunny spot where it can get the most warmth during the summer. It needs the heat in order to flower.
You should water your plants fairly regularly but not so that they are soaked all the time. Their roots do not do well when left sitting in water, so only water when the soil is dry. Excessive drought can lead to early bolting (going to seed). This is where coriander is finicky.
A fertilizer application once or twice through the season can help your plants get nice and bushy. For better seed harvests, you might want to use a low-nitrogen formula or you will end up with a plant that is all leaves and no flowers.
If you are growing your plants solely for the leaves, you may want to trim out the budding flowers in order to keep the plant growing new leaves longer. Once the plant flowers, it will stop producing new leaves. Of course if you intend to harvest the seeds as well, then you will have to let the flowers develop.
To keep your plants going year after year, let one or two flowers dry on the plant so that the seeds are dropped naturally. Coriander will sprout easily without assistance and you will have new plants each year. This will be the case, even if you don’t want more plants so take care in collecting the seeds.
You can grow coriander in pots, providing they are at least 18 inches deep to allow for the main taproot to grow.
Add extra gravel to the bottom of the container to allow for additional drainage. Coriander will suffer if the roots are left in water at all.
For cilantro, you can even grow your plants indoors if you have a sunny spot. But your home probably won’t have the necessary heat to prompt your plants to flower and produce seed. So if you are looking to get a harvest of coriander seed, you’ll have to grow your plants outside.
Pests and Diseases
Coriander is a very fast growing plant and can usually tolerate any insect pests that decide to lunch on their leaves.
There are a few other issues you may have, so you do still need to keep an eye on your plants. Powdery mildew can grow on coriander leaves, just like most other leafy garden plants. It means their leaves are too wet most of the time, and the fine dusting of white fungus can be treated with fungicides. Try watering the plant down at the soil. If it’s a problem, you may need to prune back your plants to allow for better airflow.
Harvest and Storage
For harvesting cilantro, you can start to pick leaves from each plant once it reaches around 4 inches in height. Only take a few leaves at a time until the plant is large enough to handle it. Cut the larger outside leaves first as they have the most flavor.
For the coriander seeds, you can harvest them once they just start to turn brown. It’s usually about 3 weeks after the plant blossoms. The traditional way of gathering the seed is to snip off the entire stem. Then put the seed clusters in a paper bag, and hang somewhere well-ventilated. The seeds will finish drying and you won’t lose any. They are ready to use when completely brown and dried.
As an annual, coriander won’t survive a cold winter but your plants will handle a few light frosts well. So there is no immediate need to rush out and harvest everything when the first frost is due.
Store your fresh cilantro in the refrigerator for about 2 weeks. It stores better if you keep it moist with a damp paper towel in a plastic bag. You can dry the leaves but they will lose nearly all of their flavor if stored that way. Freezing is the better choice for long term storage.
As for the seeds, once they are dry you can just store them in an airtight container. It’s best to store the seeds whole. If you prefer to use them ground, wait until its time to use them to grind.