You can definitely divide irises in the fall! In fact, late summer and early fall are considered the ideal times to dig up and divide your bearded iris clumps. This is because the weather is usually cooler and the plants have finished blooming for the season.
Dividing irises is an important task to ensure the health and vigor of your plants. Over time, iris clumps can become crowded, leading to reduced blooming and overall decline in plant health. Dividing them allows you to rejuvenate the plants, promote better air circulation, and prevent diseases.
To divide your irises, start by digging up the entire clump using a garden fork or shovel. Be careful not to damage the rhizomes, which are the thick, fleshy root-like structures that store nutrients for the plant. Once the clump is lifted, gently shake off the excess soil to expose the rhizomes.
Next, examine the rhizomes and identify any sections that appear healthy and have multiple fans of leaves. These are the divisions that you will be separating and replanting. Use a clean and sharp knife to cut the rhizome into smaller sections, making sure each division has at least one fan of leaves and healthy roots.
Before replanting the divisions, it’s a good idea to trim the leaves back to about half their original length. This helps reduce stress on the plant and conserves energy while it establishes new roots. You can also trim any damaged or diseased-looking parts of the rhizome.
When selecting a spot to replant your iris divisions, choose a location that receives full sun and has well-draining soil. Iris plants thrive in these conditions and will produce the best blooms. Dig a shallow hole, making sure the top of the rhizome is level with the soil surface. Space the divisions about 12-18 inches apart to allow for future growth.
After planting, water the divisions thoroughly to settle the soil and help them establish new roots. It’s important to keep the newly divided plants consistently moist for the first few weeks to aid in their recovery. However, be cautious not to overwater, as excessive moisture can lead to rotting.
It’s worth noting that irises generally prefer being left undisturbed for several years between divisions. However, if your irises are not blooming as well as they used to or if the clumps are becoming crowded, dividing them in the fall can greatly benefit their overall health and performance.
Dividing irises in the fall is a task that may require some effort, but the rewards are well worth it. Not only will you have healthier and more productive plants, but you’ll also be able to share the divisions with friends and family or even start new iris beds in different areas of your garden.
Remember, each iris division has the potential to grow into a beautiful and vibrant plant, bringing joy and color to your garden for years to come. So, don’t hesitate to roll up your sleeves and get digging this fall!