Cilantro, Coriandrum Sativum, may be grown from seed sown early indoors and transplanted outside or sown directly in the garden. Cilantro plants grow very well in containers and can also be grown indoors as house edible plants. In culinary terms, the seeds of the cilantro plant are called coriander and the leafy green part is called cilantro.
How to Sow and Plant
Cilantro may be grown from seed sown indoors and transplanted outside after your last frost date or sown directly in the garden once soil temperature has reached 40 degrees F. Cilantro plants can also be kept as potted specimens, either indoors or outdoors.
Sowing Seeds Indoors
Because it develops a taproot, cilantro doesn’t like to be transplanted. It grows very quickly, and a little frost doesn’t harm it, so it should be sown directly in place whenever possible.
If you insist on starting cilantro plants indoors, make sure not to disturb the roots at transplant.
Sow cilantro seeds indoors 6-8 weeks before the average last frost date in spring using a seed starting kit.
Sow seeds ¼ inch deep in seed starting formula
Keep the soil moist at 70 degrees F
Seedlings will emerge in 7-10 days
As soon as basil seedlings emerge, provide plenty of natural light on a sunny windowsill or grow under fluorescent light on a 12 hours cycle.
Transplant cilantro plants in the garden after a period of “hardening”, increasing the seedling’s exposure to sunlight gradually over a one-week period. Seedlings are ready for transplants when they have 3 to 4 true leaves.
Do not allow cilantro plants or seedlings to dry out completely until well established.
Sowing Seeds Outdoors
Direct sow in average soil in full sun as soon as 2 weeks before your last frost date. Slower germination will occur with lower temperature.
Sow seeds evenly and cover with ¼ inches of fine soil.
Firm the soil lightly and keep evenly moist.
Seedlings will emerge in 7-10 days.
Thin to 6-8 inches apart when seedlings have three pairs of leaves.
How to Grow
Select a location in full sun to partial shade and well-draining soil.
Do not allow the plants to suffer drought. Plant or sow directly in average, well-draining garden soil and keep free or weed competition.
Cilantro does not need overly fertile soil, but a nitrogen deficiency will result in a poor harvest of leaves.
Harvest cilantro leaves before the flower stem has developed.
Harvest coriander seeds once they start turning from green to gray-brown. Green seed pods can also be used fresh in cooking.
Exposure to high temperature or drought will hasten the formation of the flower stem and reduce the cilantro yield.
To dry cilantro leaves, cut whole stems on a dry morning. Tie stems loosely together in small bunches and hang in a dry, airy location out of the sun. Cilantro may also be dried on a cheesecloth or a window screen in a dry, shady location. When thoroughly dry, store in a tightly sealed glass jar in a dry, dark location.
Cilantro can also be frozen. Clean leaves can be frozen on a cookie sheet then placed in a sealed freezer bag. Another great preservation method is to mince the cilantro leaves and mix them with olive oil, then freeze the mixture in ice cube tray. The cubes can then be transferred to a sealed bag and kept for up to 8 months in the freezer.
Coriander seeds can be collected as soon as they turn from green to brown/tan. Dry them up some more in a covered location before placing them in a sealed jar to prevent mold from forming due to the residual moisture.
Common Disease and Problems
Bacterial Leaf Spot
Causes: Soil born bacteria get into contact with the plant by water splashing during watering or rain events.
Symptoms: Brown or black spot that appear on the bottom of basil leaves and streaking of the same color on the stems. Diseased leaves die and fall off. If the infection is severe on the main stem the plant may die. The condition thrives in high humidity and cooler temperatures.
Solution: To prevent Bacterial Leaf Spot avoid planting basil in the same location in the future. Applying mulch to prevent water from the soil to splash to the underside of the leaves during watering can be of tremendous help. Do not use overhead watering if possible.
Symptoms: Also called gray mold, this disease causes a brown to gray fungus to spread on plant leaves and stems.
Causes: Soil born fungus is naturally present.
Solution: Remove infected plants and plant debris, clean tool before and after working with diseased plants. Ensure good air circulation between plants.
Symptoms: This is one of the most common problems when starting plants from seed. The seedling emerges and appears healthy; then it suddenly wilts and dies for no obvious reason.
Causes: Damping off is caused by a fungus that is active when there is abundant moisture and soils and air temperatures are above 68 degrees F. Typically, this indicates that the soil is too wet or contains high amounts of nitrogen fertilizer.
Solutions: Use well-draining soils to reduce fungus proliferation.
Symptoms: Leaves turn yellow around the middle vein as the disease spreads, eventually turning grayish purple and fuzzy.
Causes: Naturally present and airborne pathogen. The condition thrives in humid conditions.
Solutions: Remove infected plants and plant debris, clean tool before and after working with diseased plants. Ensure good air circulation between plants.
Symptoms: Poorly performing plants. Wilting and poor growth in newly and established plants.
Causes: Classified as either a disease or pest, nematodes are microscopic worms feeding on the roots and may cause what looks like a nutrient deficiency, wilting and poor growth.
Solutions: Avoid planting in the same area as the nematodes are difficult to eradicate. Plant in containers. Introduce beneficial nematodes with predatory behavior.
Symptoms: Greenish, red, black or peach colored sucking insects that can spread disease as they feed on the undersides of leaves. They leave a sticky residue on foliage that attracts ants.
Causes: Insect infestation.
Solution: Introduce beneficial insects. Create beneficial insect habitat in and around your garden. Ladybugs are a well-known predator of aphids.
Symptoms: These are small white flying insects that often rise up in a cloud when plants are disturbed or brushed against.
Causes: Insect Infestation:
Solution: Hard to control without chemicals. Insecticidal soap may help but be sure to use one that does not harm pollinating insects. Introduce predatory beneficial insects and insect habitat in and around your garden.
Symptoms: Leave large holes in the foliage or leaves missing entirely. Slime trail left on leaves and stems. Slugs cause defoliation and can kill young plants with intense feeding. They mostly feed at night. Moist weather increases their presence.
Causes: Pest infestation.
Solution: Hand pick, at night if possible. Use slug traps either using cornmeal or beer. For a beer trap, dig a hole in the ground and place a large cup or bowl into the hole; use something that has steep sides so that the slugs can’t crawl back out when they’re finished. Fill the bowl about ¾ of the way full with beer, and let it sit overnight. In the morning, the bowl should be full of drowned slugs that can be dumped out for the birds to eat. For a cornmeal trap, put a tablespoon or two of cornmeal in a jar and put it on its side near the plants. Slugs are attracted to the scent of cornmeal, but they cannot digest it and it will kill them. You can also try placing a barrier around your plants of diatomaceous earth or even coffee grounds. They cannot crawl over these.
Plants die after blooming: This is normal. Cilantro is an annual plant that will stop producing after it produces seeds. Harvest leaves before the formation of the flower stem and harvest coriander seeds after they turn brown/tan for best crop yield.
Coriandrum Sativum varieties carried by Ethos Seed Company