Iris are traditionally lifted and divided in mid to late summer after they have bloomed. Trim them back to about six inches, gently dig up the rhizomes and discard the oldest interior sections. Save only the most vigorous outer sections to replant. They tend to make a nicer clump faster if replanted in triangles of three fans with each one pointing outward. Prepare the soil well with ample organic matter and replant the rhizomes being careful not to plant them deeply -- they should be about half way above the soil. Make a mound of soil and allow the roots to dangle down each side into the planting hole, then backfill and firm it. Water well, and keep them watered so that the soil is moist but not soggy until they are reestablished. |