Answer: When you dig bearded iris clumps to divide and replant, you should discard the old center of the rhizome and replant only the ends with healthy green growth. Separate by cutting with a knife, trim the roots and leaves to about six inches, and plant just under the soil surface in a sunny, well-drained site, in soil amended with compost or other organic matter. You may have planted some old rhizomes, and your iris may not be getting the sunshine they require. Wait until late summer or early fall to dig and transplant them to a sunnier location.
Q&A Library Searching Tips