Blooming once, blooming twice: Reblooming bearded irises

What if I told you that you can enjoy the beauty of bearded irises not just once, but multiple times a year? Thanks to reblooming bearded irises, a remarkable subset of this beloved plant species, this is entirely possible.

In my USDA Hardiness Zone 5, where winter temperatures can be quite cold, reblooming bearded irises typically produces two sets of blooms – one in the spring and another in late summer or early fall. These irises are also known as remontant irises or simply rebloomers. You can imagine my surprise when two of my irises started sending up floral shoots again! While they might not provide blooms throughout the entire growing season, having two bloom cycles in a single year is still a delightful feature that adds extended color to the garden. Gardeners in Zone 5 can indeed enjoy the charm of reblooming irises, even if it’s not a year-round spectacle.

Indeed, my ‘Pink Attraction’, after its initial spring bloom in mid-June, has continued to bloom non-stop from August 26 to this first week of October. And it’s not done!

While traditional bearded irises typically bloom in the spring, reblooming varieties surprise us with additional blooms during other seasons, such as summer and fall. This extended bloom period allows garden enthusiasts to enjoy their beauty throughout the growing season.

What are reblooming bearded irises?

For the regular iris, the rhizome that has accumulated enough reserves will see its terminal bud transformed into a floral bud. This will only develop after the winter. This process is called vernalization. In contrast, for the reblooming iris, the plant is able to produce bloom stalks after the initial flowering. Thus their floral buds can develop without a cold period.

Rebloomers are found in bearded iris as well as beardless varieties. All these hybrids possess a specific group of genes that enable them to substitute for the dominant genes dictating a single springtime bloom.

Choosing the right reblooming bearded iris varieties

Selecting the right reblooming bearded iris varieties is the first step. In most garden centers or nurseries, the reblooming quality of a cultivar is usually not stated. A little research is necessary, and perhaps ordering from a specialized nursery.

I have three cultivars in my collection, found by chance at local nurseries. Though only the first two have rebloomed this year, I remain excited about the possibilities of the third one!

  1. ‘Pink Attraction’: Its soft pink blooms have a bright tangerine beard at the center.
  2. ‘First Snowfall’: Its pristine white blooms show a touch of pale blue on the falls.
  3. ‘Harvest of Memories’: Its warm, golden-yellow flowers add a touch of sunshine to any border.

Remembering variability and personal preference

Keep in mind that the availability of specific reblooming iris cultivars may vary by region and over time. When selecting reblooming irises for your garden, consider your personal preferences for color, height and form. The wide range of choices allows you to create a diverse and visually captivating garden filled with the beauty of reblooming irises.

Influential factors for reblooming

The capacity of reblooming irises to produce flowers later in the season can be influenced by various factors, such as temperature, local climate, and care practices. It’s important to note that the number of blooms you’ll get later in the season can vary by variety and local conditions.

Additionally, it’s worth noting that reblooming irises might take a full year or even two years after planting to exhibit their reblooming capabilities. This holds true if you need to divide them in early fall, which is typically recommended every 3-4 years to maintain their vitality.

Growing tips

Caring for reblooming irises may require a little extra attention. To encourage reblooming, it’s crucial not to let your reblooming irises go into dormancy as fall approaches. Ensure they receive sufficient watering and the occasional application of fertilizer low in nitrogen and high in phosphate during the summer, following their first blooming period. However, please exercise caution not to apply this regimen to non-reblooming irises, as it may induce rot.

Unfortunately, in my garden, the remaining Japanese beetles have also discovered these late blooms, with few other food sources available. My only recourse is to vigilantly watch for these pests feasting on the delicate petals and handpick them.

Reblooming bearded irises offer a spectrum of color and beauty, where patience and care are rewarded with the joy of witnessing these elegant flowers grace your garden not just once, but twice!

For additional information. consult the Reblooming Iris Society.

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