Last Updated on June 12, 2023 by Real Men Sow
Cilantro (Coriandrum Sativum) can be grown indoors as either microgreens or full-sized plants. The plants need to be in full sunlight for at least six hours per day, or they will require supplemental lighting. They like temperatures between 50-80° F and moist potting soil.
For full-sized plants, direct seeding is preferred. Stem cuttings are an option for larger plants. Use well-draining growing media and plastic containers or glazed ceramic ones.
What You’ll Need To Grow Cilantro Indoors
Plastic pots or glazed clay are better for growing cilantro plants than terracotta. You should ensure that drainage holes are provided in the container.
- Because of their long taproot, full-sized plants thrive in deep containers. An 8-inch pot will suffice for a single plant. Three plants can be grown in one 12-inch container.
- For microgreens, choose shallow containers or trays that are wide and shallow. A tray measuring 10″ x 20″, is a good size.
Coconut coir and commercial potting mix make great substrates for microgreens or plants. They are light and retain water well, while also allowing excess moisture to drain quickly from the growing media.
- The potting soils are made up of a mixture of coconut coir, peat moss, pine bark and vermiculite. They do not contain soil. FoxFarm is our top choice for potting soil.
- Coconut coir, a renewable material, is made from the brown and/or white fibers between the coconut shell and its outer coating.
Seeds or Plants
You have many options for planting cilantro in your herb garden: you can start them from seeds, propagate from old plants, or buy young plants.
- Cilantro seeds can be grown in microgreens and full-sized plants.
- If you have access to mature plants, cutting costs nothing. However, they only produce full-sized plants.
- Young plants are the easiest, but most expensive option. They cannot grow microgreens. Only full-sized plants can be grown.
Growing Cilantro Indoors
- You can fill the containers with the pre-moistened media of your choice.
- Plant cilantro seeds at 1/4 inch depth and cover with potting soil.
- Place the container(s) where the temperature is less than 70°F.
- The soil should be kept moist, but not too saturated. Too much water can push air out of the root zone and cause oxygen deficiency.
- When cilantro seedlings reach two inches in height, thin plants will be found. For an 8-inch container, keep the best-looking plant. If they are spaced well, a 12-inch container can hold three seedlings.
From Stem Cuttings
- Cut a 4-inch stem just below a node. Remove all leaves from the bottom 2 inches of the stem.
- Allow the stem to grow in a glass of water or a jar of water until it is a few inches long.
- You can fill the containers with any pre-moistened media.
- Plant newly rooted cuttings carefully in the substrate. One cutting per 8-inch pot, three per 12-inch container.
- Sow seeds on the entire surface of the growing media in the tray by filling the container with potting soil. Standard seed trays yield the highest yield, which is why you should seed 26 ounces of seeds per tray.
- To compress the seeds, do not cover them with soil. Instead, stack a tray on top. To provide compression, place a weight such as a hardcover book in the top tray.
- Place the container(s), in an area where it is warm enough to sprout.
- After 24 hours, lightly water the soil with water using a spray bottle, mister or fine droplet watering device hose. The seeds may not be able to hold their own in a flooded tray. Water the tray once per day and make sure to check the soil’s moisture levels. Always water underwater, not overwater.
General Care Guide for Cilantro Indoors
To achieve maximum growth and yield indoor plants require a lot of sun. Cilantro requires at least 6-8 hours of direct sunlight to grow outdoors. Try to get at least that amount indoors. For herbs that require a lot of sunlight, they will thrive in south- or west-facing windowsills.
Indoor gardening is often not able to provide full-sun conditions like growing outdoors. In these cases, grow lights are recommended. To provide additional light, a simple 45-watt LED lamp can be suspended above the plant’s surface. This will prevent the cilantro from getting “leggy” because it is trying to get sunlight. The light level should be increased as the plant grows.
Cilantro is a cool-season herb. It grows well when temperatures are between 50 to 80 degrees F. To germinate seeds, temperatures must be between 55 and 68°F. Light frost can be tolerated by plants when they are grown outside, but it is important to protect them from cold drafts indoors.
The controlled environment is one of the many benefits of growing cilantro indoors. The cilantro plant goes into reproduction mode when outside temperatures rise above 85 degrees F. Bolting is when the leaves lose their flavor and become thin. Large umbrella-shaped structures that form seeds and flowers are formed.
Containers for cilantro like their potting soil to remain moist and not become waterlogged. Healthy cilantro requires proper drainage.
Full-sized plants should be watered thoroughly until the water runs out of the container. This is when the soil surface begins to dry out. Microgreen soil should be kept moist but not too wet. However, too much soil moisture can lead to problems like damping-off, powdery mildew and aphids in high seed densities.
Spray bottles are the best way to water seeds or germinate them. You can also use a plastic water bottle that has small holes punched in the lid. This is a cheaper alternative. Be patient if the soil is very dry and has trouble absorbing water. Let the water soak in before you add more water.
If you don’t have access to a water softener, rainwater or distilled water are best. However, tap water is acceptable. To remove chlorine from your water, you can fill a container with water. Let it sit for 24 hours before using.
Cilantro needs some air circulation to grow microgreens. Damping off is a disease that affects cilantro. It appears first as white mold, then shrivels stems and causes them to die. You can prevent this by using a fan to create a little air movement among the plants.
Feeding and Fertilization
It is important to maintain a fertile container for the cilantro plant. The plant has a finite amount of space and will need limited nutrients. You can add nutrients to the soil with a diluted fish emulsion. However, make sure you use the recommended amount for your container. Over fertilizing can be just as harmful!
Harvesting Your Cilantro Indoors
For microgreens, harvesting cilantro takes place on a different time frame than for full-sized plants. No matter what growing method you use, clean scissors and clean hands are essential for harvesting cilantro. After about 20 days, microgreens can be harvested. Full-sized plants can be harvested when they reach 6 inches.
Cilantro is an herb that grows annually and has a very short life span. It is not an herb that can be “cut-and-come again” and is usually enjoyed for between 8-10 weeks. The rule of thumb is to cut 1/3 of the plant each week.
For an unlimited supply of seeds, you can also directly sow them every 2-3 weeks. You can also pinch the cilantro tops to increase the plant’s longevity.