· Brent Wilson's Answer
· Hi Donna,
You can divide Iris that have been growing in containers.
The best time to divide Japanese Iris will depend on where you live and garden. Further north, the best time to do so is in early spring. In the South where the climate is warmer, you might be able to achieve good results doing it in early fall. If you divide them in fall, you want to do it early enough so that your new iris will have enough time to establish a good root system before going dormant. Then, in spring, the plants an spend their time establishing upward growth instead of downward root growth.
As with regular irises, division of the Japanese iris is pretty simple. Use a sharp knife to divide the rhizomes from one another. When dividing, cut back three-quarters of the foliage and plant large single or 2 to 4 fans, removing the old rhizomes and roots.
After dividing the rhizomes, plant them 2 to 3 inches deep in new freshly prepared garden beds or soil in containers. Keep the new plants watered regularly for two to three weeks and fertilize them with a flower fertilizer or mild organic plant food every two weeks to help the plants re-establish themselves.
I uploaded a couple pictures of Japanese Iris divisions so that you can know what they look like after having been divided.
Hope this information was helpful. Let us know if you have any further questions.