What to Do With Iris Bulbs After They Bloom

Time Frame

• Reticulata, Danford and Dutch iris bloom with crocus, hyacinths and other early bulbs, often before the last average frost date. Bulbous irises require a cool dormant period during summer. The best time to plant bulbous irises is in the fall.

Geography

• Iris reticulata and Danfords are alpine plants and Dutch irises are Northern European hybrids. All require well-drained soil and cool temperatures during summer dormancy. This is no problem in Northern gardens or where deciduous trees provide shade. Summers in their southern range in the United States, however, are often too warm and they are discarded like annuals after they bloom.

Considerations

• Short-lived, bulbous iris perennials propagate freely. Southern gardeners may lift bulbs after foliage dies and store them in a cool place for the summer before replanting in fall. Northern gardeners should lift bulbs only when bloom decreases due to crowding. Lifted bulbs should be divided, sorted and stored in a cool place and replanted in fall.