A few years ago, I got an e-mail from reader who was frustrated that their irises just wouldn’t bloom.
If you’ve ever looked at your own garden and wondered what went wrong, you’re not alone — I’ve been there too. Irises have been a part of my family’s flower beds for as long as I can remember, from my parents’ house to my grandmother’s garden.
They’re one of those low-maintenance plants that most of us can grow without much fuss. All you really need is a small patch of earth and a bit of sunshine, and you’re on your way.
It’s no wonder irises are beloved by so many gardeners, beginners and veterans alike.
Did you know the iris gets its name from Greek mythology? The goddess Iris was said to walk a rainbow path across the sky, and these flowers truly do offer a rainbow of colors in our gardens.
With more than 200 species — many of them native to North America — there’s likely an iris out there that fits your garden perfectly.
If you’ve ever dug up irises, you may have noticed that their roots aren’t all the same. Some, like the bearded, Siberian, and Japanese irises, have thick, horizontal rhizomes, while others, like Dutch and reticulate irises, grow from bulbs.
When I checked the photos my reader sent, I was pretty sure we were looking at bearded irises — maybe the same kind you have in your yard.
In my experience, moving and dividing irises works best in late summer and early fall — think July through September. If you’ve been putting off dividing your irises, now’s the perfect time.
Irises thrive in heat and dry weather, which also helps keep diseases like bacterial soft rot at bay. So, if you want your irises to come back strong, try tackling this task during those warm, dry months.
If you’ve noticed your irises aren’t putting on much of a show, it’s probably time to divide them. The healthiest irises that I have seen with the biggest blooms were in full sun.
Most gardeners find that splitting irises every three to five years gives the plants a fresh start — and a better chance at blooming next season. Don’t forget to toss in some fresh compost when you replant; your irises will thank you for the extra boost.
When transplanting irises in July, start by trimming the leaves back by about a third.
This might feel strange if you haven’t done it before, but it helps the plant focus on its roots.
Next, carefully lift the whole clump out with a spade or potato fork. I always keep a sharp knife handy and dip it in a 10% bleach solution or rubbing alcohol to keep things clean between cuts — something I picked up after a few not-so-great experiences.
Gently separate the rhizomes. You want to use younger, smaller ones for your new transplants.
The best way to transplant these healthy rhizomes is after soaking them for at least 20 minutes in a warm bucket of water. Make sure the new spot gets plenty of sun and drains well.
When planting, dig a hole about 5 inches deep and build a little mound in the center so that the rhizome is not very deep either for the Siberian or the Bearded iris.
Set the rhizome on top so it’s just barely covered with soil and compost.
Planting too deep can cause rot, so keep it shallow. Space them 18 to 24 inches apart, and if you’re like me and want things to look tidy, point all the leaf fans in the same direction.
Keeping rhizomes shallow, healthy, and well spaced really makes a difference.
Before planting, double-check your rhizomes for signs of trouble—like soft rot or iris borer.
The iris borer is a sneaky little brownish moth whose eggs hatch in spring, and you might spot its pink caterpillar inside the rhizome when you’re dividing your plants.
If a rhizome feels squishy or you can poke your finger into it, it’s probably infected. I’ve learned to always toss any questionable rhizomes and clean up old leaves in fall to help keep these pests and diseases under control.
Trust me, a little extra effort now saves a lot of headaches later.
There’s something about a rainbow that makes us stop and smile — and, in a way, irises bring that same sense of promise to our gardens. Watching them bloom after a long winter always reminds me that good things are around the corner.
I hope you get to enjoy a stroll through your garden this week, and if you have any iris stories or run into any challenges, I’d love to hear from you. My e-mail is ericlarson546@yahoo.com.
