How to Grow Cilantro Indoors
Sunlight
Cilantro likes bright indirect light but dislikes intense, direct sunlight. The best option for container gardens is morning sun in an east-facing window or a very bright sill that doesn’t get too much direct sun.
Temperature and Humidity
Cilantro bolts easily, especially in warm weather. Once cilantro bolts, the flavor changes, often becoming bitter. With potted plants, you can extend the harvest season by keeping the plants around 70 degrees and bringing them indoors to an air-conditioned environment when outdoor temperatures get warm.
Watering
Keep the soil regularly moist, but not soaked. Good drainage is essential, as cilantro has deep roots. Aim for about one inch of water per week.
Fertilizer
Use a liquid fertilizer or supplement the soil with controlled-release pellets. For organic cilantro, use organic fertilizer or fortify the soil with compost. Feed the herb once a month.
Pruning and Maintenance
As the young plants grow, periodically pinch back them by about one inch to encourage fuller plants. To extend your cilantro harvest, regularly snip soft stems, rotating the plant as you harvest to encompass the whole plant.
Container and Size
Cilantro needs a pot that is deep enough for it to take root; look for a pot at least 12 inches in depth and about 18 inches wide. A plastic pot will help hold water and keep the plant moist, feeding its desire for humid surroundings.
Potting Soil and Drainage
Cilantro does best in airy, light, fast-draining soil with plenty of perlite or sharp sand mixed in to increase drainage. In a container, use a premium potting mix rather than garden soil, which is too heavy.
Potting and Repotting Cilantro
Cilantro is an annual that grows with a deep taproot. As a result, it dislikes repotting and will often bolt at the slightest provocation. It’s best to repot your garden-center cilantro only once after bringing it home, then keep the plant in that container for the rest of its life. Seed-grown cilantro can transition from your seed-starting pot to its permanent home pot. Because cilantro is an annual, mature plants should never need repotting. A fully mature flowering cilantro plant can hit a height of 24 inches, including flower stalks.
Moving Cilantro Outdoors for the Summer
If you move cilantro outdoors, it should not be during the summer. Move it during the spring or early fall when temperatures are moderate.
Considerations
When moving cilantro outdoors, remember to keep it in a shaded area and take it outside only when there are moderate temperatures of about 70 degrees. Temperatures too high will make cilantro bolt. Pay attention to the rainfall; water cilantro only if there isn’t enough rain during any given week.
When to Bring Cilantro Back Indoors
Pay close attention to the temperature. When it begins to dip into the 60s or rise into the 80s, it’s time to bring cilantro back inside to an air-conditioned space.
If you’re harvesting the seeds, clip the seed heads and put them upside down in a paper bag. Wait a couple of days, and the husks will dry, split, and drop out the seeds inside.
