Answer: Bearded iris are technically rhizomes rather than bulbs, and they do best in full sun and a well drained soil. They may need division every three to five years when they become crowded and this is best done in the summer after they have bloomed. This allows you to refresh the soil and remove any weeds that have become established as well. Weed control is important since the rhizomes need to be open to the air to prevent rotting. Mulching between but not overtop the rhizomes can be helpful with weed control as well. Remove faded foliage in the fall and early spring, trim back lanky foliage in mid summer by about half. Annual fertilizing (an all purpose complete granular such as 10-10-10 according to the label insutrctions is fine) plus an annual application of compost can help keep them in peak bloom. Keep an eye out for iris borers and signs of rot among the rhizomes. Enjoy those iris!
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