Iris Foliage In The Summer Garden

Iris foliage in the summer garden

Bearded Iris really offer so much to the mixed perennial garden. The beauty they offer in the spring is uncontested, but we often get questions about what to do with the foliage after the spring bloom has faded. Culturally speaking, the foliage must remain intact through the summer growth phase. The foliage converts the energy to feed the growing rhizomes. Shorter foliage can limit the energy conversion. That said, we ourselves trim the foliage when we prepare our plants for order fulfillment. This practice of trimming foliage is also generally followed when gardeners divide and transplant Iris in their home gardens. The shorter foliage facilitates planting — the long blades of the Iris foliage can often prove too heavy for the newly planted rhizome to bear, causing the plant to become dislodged. Established Iris, of course, with their larger root systems, can bear the weight of the foliage.

Thus, we recommend leaving the foliage untrimmed throughout the summer months. Planted among other summer blooming perennials and shrubs, the vertical lines of the Iris foliage provide a wonderful counterpoint to other forms in your garden. The images here illustrate this point. These photos were taken in our Display Gardens in late July.

Iris bed in mid-summer. Vertical lines contrast with shorter annuals and greenery.

Back in the summer of 2012, we published a blog post on the subject of planting and trimming Bearded Iris. Take a look here at that post for more details on planting and trimming.

Thank you as always for reading. How do you appreciate the Iris foliage in your garden? Post a comment below.

And take a look at our summer sale and clearance pages. Some really terrific Iris can be had for some super low prices!

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Planting & Trimming Iris: The long and short of it

First, let’s be clear: we are referring to Bearded Iris in this discussion. The myriad of other lovely Iris varieties come with their own set of operating instructions.

Our last two blog posts generated a number of very worthwhile questions. After doing a bit of reading on the subject, I came across a couple of useful bits of information. The first is a series of photos on planting Bearded Iris, see below. These come from William Shear’s, “The Gardener’s Iris Book” (Taunton Press, 1998), page 43. How deep should the rhizome be? We are in agreement with Mr. Shear on this question. “It depends,” he writes. “In light-textured soils, it can be covered by as much as 1 (one) inch of soil, but for average to heavier soils, the top of the rhizome is best left exposed to the healthful influences of sun and air. Remember that the rhizome is a stem, not a root, and needs to breathe!” You can see in the third photo below that the top of the rhizome is still peeking through the soil.

Steps for Planting Bearded Iris, “The Gardener’s Iris Book”, pg 43.

On the subject of trimming the foliage, I found a bit of tidy wisdom, the kind you keep clipped into your pocketbook, or saved on our phone, for easy reference. This comes from, “A Guide to Bearded Irises: Cultivating the Rainbow”, by Kelly Norris (Timber Press, 2012).  In his myth-busting section he addresses the question of trimming.  “Myth: Bearded irises are so much work. You have to trim the foliage back every summer!” Mr. Norris reassures us that in fact this may be an “unnecessary chore”.  There is no real need to trim the foliage in the summer, except that during dividing and transplanting shorter foliage eases the handling of the plants. He reminds readers that “needlessly trimming the foliage back in the middle of the season actually breaks an iris’s dormancy, kick-starting foliar production. This can take away from root mass accumulation and even from reserves meant to support flowering the next spring.”

The long and short of it is to plant shallow and leave the leaves alone. Thanks for reading and happy gardening!