If you have flowering iris in your garden, you should divide them every few years to prevent overcrowding and promote blooming. Irises are perennial plants that grow from tuber-like underground horizontal stems called rhizomes.
To divide irises, use a gardening fork to gently remove the plants from the ground. Discard any damaged or unhealthy looking iris rhizomes, and replant the rest.
Watch this video to find out more.