Light Required to Grow Cilantro

Full Sun

• Full sun exposure, with six to eight hours or more of sunlight, are optimal for cilantro. This intense light helps develop flavor-boosting oils within cilantro leaves. But even under full light conditions, cilantro will quickly diminish in quality once temperatures are too hot. If planting in full sunlight, make sure to protect it from soil temperatures above 75 F. Above this temperature, the plant will begin to bolt, sending its energy into flower production and diminishing the flavor of its leaves. Temperatures between 50 and 80 F should be maintained for best results.

Light Shade

• Plant cilantro in light shade, where sun is filtered, for high-quality leaves in summertime and in warm weather. Under these conditions, the plants will receive five to 10 hours of direct, filtered sun. When temperatures get too hot, this partial shade location will prevent cilantro from bolting and leaves from growing bitter. But if you are growing the plant for its coriander seed, plant in full sun. With less sunlight, shade-grown cilantro may be less productive, but will still produce tasty leaves even during hot weather.

Indoors

• Like many herbs, cilantro is also productive when grown indoors under fluorescent lights or on a windowsill. Set fluorescent lights 4 to 6 inches above young seedlings for 14 to 16 hours daily. Once established, provide 12 hours of artificial light every day to promote vigorous plants. Raise the lights as the seedlings grow taller, then transplant outdoors when established. Or, keep the cilantro indoors for continuous indoor production. Alternatively, place plants in a window that receives full sun exposure.

Bolting

• To prevent cilantro from turning to coriander seed, some shade may be necessary, particularly in summertime or when temperatures are above 80 F. Providing extra moisture and mulching around the base can help protect the roots from getting too hot. Plant cilantro in early spring or fall to avoid hot summer temperatures. Otherwise, plant cilantro in partial shade or indoors near a sunny window to avoid bolting.