Coriander (Coriandrum sativum) is one of the world’s most popular and used herbs. We grow coriander from seeds continuously throughout the season. Here in this article, we will share our best tips and techniques.
Fun fact: Where we live and grow both seed and leaves are known as coriander. But in large parts of the world, the green part of the plant is called cilantro whereas the seed is called coriander.
The coriander leaves – or cilantro – are sometimes confused for flat-leaved parsley, but the distinct smell and taste take care of any risk of mixups.
Coriander is a fast-growing annual plant and lends itself well to being planted continuously throughout the season.
We start planting seeds in pots in February / March and then new batches every 2 to 3 weeks. If the leaves go yellow due to lack of light, we use LED grow lights. This allows us to have access to coriander pretty much throughout the year.
How to grow coriander
Coriander can be grown indoors in pots or directly in your herb garden.
Coriander seeds are resilient to cold. Still, we always wait for a ground temperature of about 10 degrees Celsius (50 degrees Fahrenheit) before planting seeds in our herb garden.
Planting seeds directly in your herb garden is relatively straightforward. When you plant seeds outdoors, I recommend creating a line in the ground approximately 1 cm (1/2 inch) deep. Water the soil, plant the seeds in the already wet soil, and cover lightly with fresh soil.
Coriander develops a delicate central taproot. To avoid transplanting seedlings later, leave about 20-25 cm between the seeds if you have space.
Keep the soil moist but not wet. Use soil with a lighter structure to allow for good drainage. Avoid complete dry outs, especially in the hot summer months, as it stresses the plant to bolt and goes into earlier blooming.
Coriander is easier to grow during the shoulder seasons and is prone to bolt during the hotter summer months. If your coriander plant starts to develop flowers, remove them to ensure all energy goes into producing more new and tasty coriander leaves.
The coriander plant likes a light location but does not crave direct sunlight like the cherry tomato, beefsteak tomato, or pepper plants.
Grow coriander from seeds in pots
If you start your seeds indoors, you will have a longer growing season and a much fuller harvest.
And it is simple and low maintenance.
1. Choose a pot
I prefer using plastic starter pots from recycled materials (7 centimeters or 3 inches) that I have had for years.
Plastic pots help keep the soil moist and prevent drying out.
I have used peat pellets and pots made from porous materials, but they are more expensive, and you need to water more, especially on hot days.
2. Choose your soil
You can use regular well-draining potting soil mix when planting your seeds.
I prefer to use a mix of equal parts of cactus soil mix and regular potting soil when I plant coriander seeds in pots.
The cactus soil has a looser texture and helps me control soil moisture and the level of nutrition.
Pay attention when you choose your potting soil. Commercial potting mixes are sometimes amended with fertilizer or compost. And there is, of course, a time and need for that.
But I have in the past had seeds “burn” from too much nutrition that damaged the new roots and prevented the seedlings from developing.
3. Fill the pot with soil
Next, fill the pot with soil and water. Let the water run through the soil to wet it without making it soaking wet.
If the soil loose too much volume, add more and gently firm using your fingers.
Well-draining soil finds the correct moisture level if you leave the pot alone for excess to run off.
4. Plant your seeds
Plant the coriander seeds about 1 cm (1/2 inch) deep.
I always plant many seeds and worry about transplanting the seedlings when they are large enough to handle.
Coriander has a reputation for being difficult to transplant due to its delicate taproot. I have, however, not had any problems when transplanting the whole pot with the root system, soil, and all.
But do take care to space out the seeds as each seed will form a plant. And it is complicated and risky to separate seedlings growing together tightly in a group.
Coriander seeds can take up to 3 weeks to germinate. I have compared starting soaked seeds, crushed seeds, and seeds straight out of the seed packet. And gently crushed seeds (1 seed into 2 or 3 parts) germinate faster.
I compared 3 different ways to germinate coriander seeds in a different article. And it was conclusive that gently crushing the seeds would make the coriander seeds germinate faster. Soaked seeds came in second place whereas planting the seeds straight from the packet took the longest time to germinate and sprout first leaves.
If you have the space, you can plant one seed per pot already at the beginning.
The coriander plant needs about 20-25 cm (8-10 inches) of growing space to develop properly.
5. Keep moist
Now we wait, and our only job is to ensure that we keep the soil moist but never soaking.
We must also avoid complete dry-outs to avoid stressing the plant to bolt and bloom earlier.
6. Transplant to larger posts
If you plant one seed per pot, you can skip this step.
But as I always plant 3-5 seeds per pot, I need to transplant the seedlings to bigger pots as they develop.
My rule of thumb is to transplant the seedlings when they are about 5 cm (2 inches) tall.
I try moving a seedling, and if it turns out to be too brittle, I wait a bit longer. And since I plant many seeds, I can afford to lose a few seedlings.
I transplant 3-5 seedlings at this stage into a 20 cm (8 inches) pot.
7. Transplant the developed seedling
When the seedlings have developed to about 10-15 cm (4-6 inches), it is time to transplant them to their final growing place.
I allow 20-25 cm (8-10 inches) between the seedlings or plant one seedling per 20 cm (8 inches) pot.
If you plant rows of coriander seedlings, you should space the rows about 30 cm (12 inches) apart.
8. Harvest coriander after 6-8 weeks
You can harvest coriander leaf by leaf or cut the entire plant after about 6-8 weeks.
A fully matured coriander plant reaches approximately 70 cm (27 inches).
I grow coriander in several medium-sized pots measuring about 15 centimeters (6 inches) in diameter.
When I harvest the plant, I cut the entire plant leaving the stems about 3 centimeters (1 inch). I keep the pot in the exact location and continue caring for it. And the plant will always grow back and provide more beautiful leaves to harvest.
By using several medium-sized pots, I always have fresh coriander when needed.
9. Use fresh coriander or preserve it for future use
Fresh coriander is, among other things, used in dishes from Mexico and Southeast Asia.
The coriander leaves can also be preserved in the freezer for later use. The herb does not dry well and tends to lose a lot of its flavor.
Harvest coriander seeds for planting
Preparing for next year’s planting season starts with planting seeds and then allowing the seedling to develop into a plant undisturbed.
The coriander plant will form flowers earlier when we do not harvest leaves.
When we see seeds forming, we wait for the seeds to change from a green to a light yellowish tone.
When about half the seeds have turned color, we cut the stems and bunch them together with string.
Then put the bunch of coriander stems in the paper bag and tie the paper bag’s opening around the stems.
Now hang the paper bag with the stems in a dry spot and let the seeds fall into the bag as they dry.
Fresh green coriander seeds do not smell pleasant, but the smell disappears as the seeds dry.
When the seeds are dry, we store them in a dry and dark place until it is time to plant coriander seeds again.
Coriander seeds are edible and have a more robust flavor with a nutty character.
