The best time to divide chives is in spring after the leaves have emerged and grown 3 to 4 inches tall. To divide, start by digging up the entire clump of chives using a sharp spade. Set the chives onto the ground and gently tease the clump apart, separating it into smaller sections with 5 to 10 bulbs per section.
Replant the smaller sections in a sunny location with well-drained soil, spacing the plants 6 inches apart and setting them at the same depth as the original clump. If you have more divisions than you need, pot up the extras in a container and give them to friends, or just toss them into your compost pile.
Wait to harvest for one month so the divisions have time to establish. Then, harvest leaves regularly by cutting them off with scissors 2 inches above the ground. Frequent harvesting encourages the formation of new bulbs and ensures succulent, tender leaves.