Although the entire cilantro plant is edible, the leaves are commonly used as a seasoning in food. Use your fingernails to pinch off the leaf at the main stem.
Harvest the cilantro leaves as soon as they form and throughout the spring and early part of the summer before the plant blooms and goes to seed. Pinch the leaves in the morning and keep in water, similar to a fresh cut flower, until ready to use. This period between planting and blooming, the period cilantro leaves can be harvested, lasts about two months or until soil temperatures warm to about 75 degrees Fahrenheit.
Plant separate batches of cilantro seeds in the garden about four weeks apart. This guarantees a continuous supply of the herb fresh from the garden. Even growing a few plants at a time is commonly sufficient as the leaves have a strong flavor.
Some gardeners allow the cilantro plant to bloom and go to seed. Once the seeds have turned brown, cut the entire plant off at ground level. Place the plant upside down in a paper bag and hang in a dry area. As the plant and seeds continue to dry, the seeds will fall and accumulate in the bottom of the paper bag. Winnow out any dried leaves and debris and the remaining seeds can be ground for coriander.