Cilantro needs its own space in the garden where you can harvest it and then let it go to seed.
Cilantro produces excellent microgreens
It grows fast in the cool weather of spring and fall, creating a rosette of lacy leaves. When the weather gets warm, the plant sends up a long, lanky flower stalk bearing flat umbels of white or pinkish blossoms which later produce coriander seeds. Plant cilantro in a bed devoted to herbs where it can reseed, or in a corner of the vegetable garden.
In mild climates, cilantro makes a handsome winter companion to pansies. Leaves withstand a light frost.
Grow cilantro in full sun and well-drained soil with a pH of 6.2 to 6.8; it will tolerate light shade in the South and Southwest where the sun is intense. In the South and Southwest, plant 12 to 18 inches apart in the fall or the spring about a month before the last frost. Fall is the ideal time to plant in zones 8, 9, and 10 because the plants will last through until the weather heats up in late spring. When plants begin to bloom, the foliage becomes scarce; for steady harvest, set out plants every 3 to 4 weeks until the weather gets warm in spring, or until the first frost of fall.
Garden Planting: Cilantro frequently self sows. As seeds fall to the ground, little plants often come up during the season and the following spring. The standard directions are to sow cilantro about 1/4-1/2" deep, but there is no need to get scientific about it. Just cover the seeds and keep them moist.