Answer: Sounds like cultural or environmental stress, especially if the leaves are also stunted. This condition could be caused by lack of sunshine, overcrowding, or even poor soil. The normal time to dig and divide iris is after their bloom, but it's early enough in the season that if you dig them up now they may still bloom on time. Carefully remove all the rhizomes from the bed, break off and discard the old ends and save the healthy middle sections. Then amend the bed with 2"-3" of organic matter, digging it 6"-8" into the soil. Replant the iris just below the top of the soil surface and water them in well. The organic matter will supply nutrients to the roots of the plants and help the soil retain just the right amount of moisture. Water the iris bed regularly during the growing and blooming season. Cut off the flowering stalks when the flowers are spent, then reduce watering late in the summer. Your iris should recover and produce tall stems with multiple flowers.
Q&A Library Searching Tips