Dividing and Transplanting Irises

The sun’s returned today after a blustery and extremely cold day yesterday, so it’s suiting to celebrate some sunny news. Teddi‘s team has finished dividing and transplanting irises from the flower bed outside Rosslyn‘s mudroom. Hurrah!

Undaunted by the inclement weather, these intrepid women efficiently executed 3/5th of the project that they began last autumn in a day and a half. Efficiency exhibit A!

But I’m getting ahead of myself. Let’s start out with the importance of dividing and transplanting irises for plant health and propagation.

Why & When to Divide Irises

Let’s start with the photograph above. The lower tier of this mature flower bed (located just outside Rosslyn’s mudroom) was lush with bloom in the June 1, 2022 photograph. Although my decision to plant this combination of perennial blooms thus pre-dates by a decade and a half my reading of Robin Wall Kimmerer’s Braiding Sweetgrass, the the golden irises and purple lupines take me to the heart of her enchanting work.

That September pairing of purple and gold is lived reciprocity; its wisdom is that the beauty of one is illuminated by the radiance of the other. Science and art, matter and spirit, indigenous knowledge and Western science… When I am in their presence, their beauty asks me for reciprocity, to be the complementary color, to make something beautiful in response.

— Robin Wall Kimmerer, Braiding Sweetgrass

If subtle and extravagance were to bear a lovechild, it very well might be this flowerbed of golden irises and purple lupines. But this breathtaking bed conceals a secret.

Although it’s early enough that the third variety, Shasta daisies, is invisible in this early summer capture, a close look at the foliage will reveal virtually none of the white bloomed plants. They are being choked out. The lupines and iris are thriving, but the Shasta daisies are struggling to survive.

Once upon a time, all three varieties were interspersed equally. At times the entire bed would bloom white with subtle yellow centers. At other times, the entire bed looks as it does above, golden irises and purple lupines. 

Both iris and lupine are aggressive, and both benefit from division and transplanting. When plants are becoming marginalized, blooms are decreasing, and/or the rhizomes are becoming crowded, it’s time to divide and transplant.

In the case of iris, the optimal time for dividing and transplanting is early fall. And so, on September 18, 2024, Teddi’s team began the project.

Dividing Iris Rhizomes

There are plenty of resources available to guide you, step-by-step, through the lifting and division of iris rhizomes, so I won’t duplicate efforts. Here’s simple overview:

• Using a fork or spade, lift clumps of iris rhizomes free from the soil.
• Gently loosen and remove soil as you separate the crowns from one another.
• Select the healthiest and most robust for transplanting, and discard or compost older, weaker crowns.

Now it’s time to pick a location for planting. In our case, we wanted to replant this flowerbed, and extras were scheduled for transplanting to ADK Oasis Lakeside and ADK Oasis Highlawn.

Transplanting Iris Rhizomes

Time out of ground is a consideration at this point. In our case, Teddi’s team turned the disinterring-to-reinterring timeline into a swift 24 hour adventure. Impressive! But don’t worry if you need a little more time. It may be necessary to re-spritz the rhizomes from time to time, and you’ll best keep them stable at lower temperatures. But as long as they don’t start growing significantly during the process, you’ll be fine.

I’d recommend you consult variety/size specific guides with respect to trimming, spacing, and planting depth recommendations. Ditto for any mulching considerations and watering guidelines to help support establishment of your transplanted irises.

Congratulations Teddi & Co.

I mentioned earlier that yesterday‘s weather was miserable. Cold. Windy. Damp. Everybody was bundled up to keep warm. Needless to say, the conditions were decidedly suboptimal for dividing and transplanting irises. But Teddi and two of her resolute Amish assistants soldiered on. Today’s more temperate conditions offered a more pleasant opportunity to finish transplanting and marking the irises.

Susan and I are thrilled with the turnaround, and we’re looking forward to bountiful blooms soon. Thank you!