Full Sun, Rich Soil Suit Cilantro

Question: How much light, sun and water does cilantro need to grow?

P.C., Mission Viejo

Answer: Cilantro (coriandrum sativum) prefers rich well-drained soil and full sun. This herb grows quite readily from seed but doesn’t transplant well, so it is best to sow it directly into the garden.

The seeds are fairly large (size of a peppercorn) and many gardeners find increased germination rates by scratching the seed coat or soaking the seeds. Generally, they are planted a quarter-inch deep and thinned to 12 inches apart. Sow cilantro every few weeks for a continuous supply.

Cilantro does best if grown in the cooler months of fall, winter and early spring. When planted in the warmer months, the foliage turns a sickly yellow color, the plant flowers, sets seed and dies.

To successfully grow cilantro in summer, you will need to make successive sowings a week apart in the coolest part of the garden in part shade. To delay seed formation, pinch off flower buds as they begin to form, avoid crowding the plants, and harvest frequently.

You may, however, want to let some plants flower and go to seed, as their lacy blooms attract “good bugs” to your garden, which keep the “bad bugs” in check.

Regular watering is imperative for healthy plants. Keep the soil moist once seedlings appear.

The fresh leaves of this plant are called cilantro (Chinese parsley) and are essentials in Mexican and Asian dishes. The seed that forms is known as coriander. Coriander is frequently ground and used in tuna salads and is a key ingredient in chili and curry powders. Fresh cilantro leaves and dried coriander seeds are not interchangeable.

Harvesting of cilantro leaves can begin about six to eight weeks after the plants first appear. After harvesting, lightly fertilize with fish emulsion or other liquid fertilizer to stimulate new growth. Avoid overfertilizing, as this can lead to lush foliage but decreased flavor.

Harvest seeds just as they begin to turn brown. Spread them out to dry or hang them upside down in a dry, well-ventilated room and allow the remaining seeds to ripen. In about two weeks, collect the dried seeds; remove any bits of stalk and store seeds in an airtight container.

“Slow-bolting” cultivars such as ‘Jantar’ or ‘Santo’ (though a bit hard to find) may help extend leaf production by several weeks.

Save any leftover seeds. If properly stored, coriander seeds remain viable for five to seven years.

Have a problem in your yard? University of California Cooperative Extension (UCCE) Master Gardeners are here to help. These trained and certified horticultural volunteers are dedicated to extending research-based, scientifically accurate information to the public about home horticulture and pest management. They are involved with a variety of outreach programs, including the UCCE Master Garden hotline, which provides answers to specific questions. You can reach the hotline at (714) 708-1646 or send e-mail to ucmastergardeners @yahoo.com. Calls and e-mail are picked up daily and are generally returned within two to three days.