The days are getting shorter and temperatures are dropping, but iris rejuvenation is underway in the Buttrick Gardens. Beginning in August, park staff and volunteers lifted and divided hundreds of bearded iris rhizomes. “Iris rhizomes should be divided every 2 to 3 years,” explains Park Resource Manager Margie Brown.
This past spring, Friends of Minute Man horticultural intern Sophie Cooke mapped and labeled the iris in bloom throughout the gardens, recording 24 distinct cultivars. However, some iris did not bloom due to crowding. Margie Brown adds, “By lifting, dividing, and spacing the iris, we will ensure all cultivars are preserved and we may discover additional cultivars.”
Where are the extra iris rhizomes going? While many are remaining in the main garden beds, surplus rhizomes are planted in vacant beds in the West Slope Garden. Divisions are planted in amended, well-drained soil and spaced six to eight inches apart. When planted, the rhizomes must be half exposed on the surface of the soil. Margie Brown explains, “After a good watering, you should be able to pat each iris on its back (the exposed rhizome). We hope our efforts and encouragement will be evident in the coming spring!”
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Click here to learn more about the iris rejuvenation and mapping project.
Images above: Iris blooming in the Buttrick Gardens in May-June 2022. Iris propagation, showing how the top of the iris rhizome sits above the soil.
Image below: Dun & Bradstreet employees provided a day of volunteer service and assisted with the division and replanting of the iris, pictured here in the west slope garden.