Answer: You may have iris borers. These moth larvae, hatched from eggs laid in old iris stalks and garden debris in late autumn, emerge in the spring as tiny caterpillars. They bore into new iris leaves and eat the soft interior tissue, gradually working theirway down into the roots. The borers not only damage the plants with their chewing but carry the bacteria that produce foul-smelling soft rot, one the serious diseases that affect irises. Clear iris beds of old leaves and stems, where borers lay their eggs in the fall. You may need to spray young plants with a pesticide in early spring, before the borers enter the leaves. Make sure the iris are not receiving too much water..this will also encourage rot.
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