If you are looking for the best time of the year to transplant Louisiana irises, wait until fall. It isn’t now when the heat is upon us.
But occasionally, you have to move irises in the summer, or perhaps you are gifted some bare root rhizomes and want to make sure they live. Here’s our best advice:
- Hold the rhizomes in a shallow pan of water until you are ready to deal with them. The rhizomes and roots should be underwater, but the foliage should not, so a couple of inches of water is advised.
- Pot the rhizomes instead of planting them out into the garden immediately.
- Keep the pot in a shady place and well-watered. Setting the pot in a few inches of water is a good approach, so the plant can draw up constant moisture. Don’t place the whole pot under water and submerge the rhizome itself.* An 8 or 10-inch pot sitting in 2 inches of water is fine.
- Keep water in the container so the rhizome does not dry out.
- Keep the irises in pots until you see that leaf growth has resumed. That may not be until late summer or early fall.
- Plant the irises in the garden in the fall (late August, September or October).
- You could fertilize the potted irises with a liquid fertilizer or with a time-release granular fertilizer, but it may not take off and grow much until the fall.
*Even though Louisiana irises are wetland plants and will grow in standing water, the rhizomes can rot if the plant is not established with its roots growing in soil. You can plant a potted iris into water, but bare root rhizomes are difficult to establish by directly planting into a pond or similar situation. The mucky edges of a pond do work well.
