A large clump of bearded iris needing to be divided

Such a large clump of bearded iris must be divided



Dividing the rhizomes of bearded iris plants is an easy and necessary process as the plant ages. The division process is best done during late summer or early fall, but we are doing this job now on our farmette.


The rhizome is a thick tuberous type of structure that sends up stems and leaves and also produces roots. Many gardeners divide their iris clumps every three to four years. Our beds of iris have become overcrowded with many new baby plants. It’s time to divide.



The soil with fertilizer added should ensure a healthy start to the iris

Good top soil with low-nitrogen fertilizer ensures the iris get off to a good start



Before we move our iris from the side garden to planter boxes made of pressure-treated redwood, we prepare the soil in those boxes. We amend it with low-nitrogen fertilizer and compost.



The newly planted iris will reward us with dazzling blooms around Easter

These iris are planted too close–they will be replanted to¬† 16 inches apart for air to circulate and for growing room




We cut back the foliage and pull off any of the sword-shaped leaves that have dried. Then we gently pull apart the new growth from the old clump. Pruning and cutting back the leaves helps ensure that pests do not overwinter.


You might expect purple iris to bloom around Easter but in late October?

These purple iris bloom in our garden in spring, making a lovely arrangement with roses



The rhizome produces more rhizomes over time. Eventually the original rhizome will wither and die. Regularly dividing the clumps ensures new baby plants and blooms for years to come.





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