When to separate Bearded Iris bulbs?
Bearded irises don’t grow from bulbs – they grow from tubers. These are kind of lumpy brown roots that grow along the surface. You can dig these up and separate them into pieces. As long as each piece has some leaves and roots, they should survive. The tubers should be planted so that the leaves are on the north side, and the tuber is exposed on the surface. Flowers develop best when the tuber is baked by the summer sun. It is a bit late, but not too late to be dividing irises. The best time is soon after they have flowered. As for true spring bulbs, the best time to divide and transplant them is in the fall (September-October). If the bulbs are small they may not flower next spring. You need to get some good leaf growth in the spring and early summer to develop good-sized bulbs that will flower the following year. Don’t dig up bulbs and store them in a refrigerator. The best place for them is in the ground.
