Why do we dig and divide irises rhizomes?

 

Digging and dividing irises is an important task that helps rejuvenate the plants, prevent overcrowding, and promote healthier blooms. Here's a step-by-step guide on how to dig and divide irises:

1. Timing: The best time to dig and divide irises is typically in late summer to early fall, after the plants have finished flowering. This allows the plants time to establish new roots before winter.

2. Tools needed: Gather the necessary tools, including a garden fork or shovel, a sharp knife or garden shears, a hose or bucket for washing and soaking the rhizomes, and any additional supplies for replanting.

3. Prepare the soil: Choose the new planting location for your divided irises and prepare the soil by removing weeds, rocks, and debris. Amend the soil with compost or well-rotted manure to improve fertility and drainage if needed.

4. Lift the clumps: Gently lift the clump of irises by inserting a garden fork or shovel into the soil about 6 inches (15 cm) away from the edge of the clump. Carefully lift the clump out of the ground, trying to keep the rhizomes intact. Shake off excess soil or gently rinse the clump to reveal the rhizomes.

5. Divide the rhizomes: Examine the clump and identify healthy rhizomes for division. Look for firm, plump rhizomes with roots and fan-like leaves. Use a sharp knife or garden shears to separate the rhizomes. Each divided rhizome should have a fan of leaves and healthy roots attached. Discard any soft, mushy, or diseased rhizomes.

6. Trim and clean the rhizomes: Trim the leaves of each divided rhizome to about 6-8 inches (15-20 cm) in length. Remove any dead or yellowed leaves. Rinse the rhizomes in clean water to remove excess soil or debris.

7. Soak the rhizomes: Prepare a bucket or container of water and place the cleaned rhizomes in it to soak for about 1-2 hours. This helps hydrate the rhizomes and reduces transplant shock.

8. Replanting: Plant the divided rhizomes in the prepared soil, ensuring that the top of each rhizome is level with the soil surface. Space the rhizomes about 12-18 inches (30-45 cm) apart to allow for their spreading growth habit. Gently firm the soil around the rhizomes to provide good contact with the roots.

9. Watering and mulching: Water the newly planted rhizomes thoroughly to settle the soil and provide moisture for root establishment. Keep the soil consistently moist during the first few weeks after replanting. Apply a layer of organic mulch around the plants to help retain moisture, suppress weeds, and regulate soil temperature.

10. Care after division: After dividing and replanting, continue to care for the irises as usual. Provide them with adequate sunlight, regular watering, and fertilization as needed. Monitor for pests or diseases and take appropriate measures if any problems arise.

By dividing your irises every few years, you can maintain their health, promote better flowering, and expand your iris collection. With proper care, your divided irises should thrive and bring beauty to your garden.