Ep 204. Dividing Iris and Multiplying Gifts

Mary Stone discusses how and when to divide iris to improve plant health and increase blooms. She also shares the history of her gifted iris and other plants, some of which are not her favorites.

Mary suggests native alternatives to Stella Dora Daylilies and Bearded Iris but accepts gifted ornamental plants if they are not invasive or harmful to the environment and encourages folks to aim to have 80% native plants in their gardens.

She concludes by inspiring listeners to share stories about plants they were given and the special people who shared them by emailing her at AskMaryStone@gmail.com.

Related Podcasts and Posts: 

Dividing Iris and Multiplying Gifts  - Blog Post 

Ep 201. Dividing Perennials and Sharing Growth

Dividing and Sharing Perennials - Blog Post

Ep 47. Personal Growth with Houseplants

Personal Growth with Houseplants - Blog Post 

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I'd love to hear your garden and nature stories and your thoughts about topics for future podcast episodes. You can email me at AskMaryStone@gmail.com.

You can follow Garden Dilemmas on Facebook and Instagram #MaryElaineStone.
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Thank you for sharing the Garden of Life,
Mary Stone, Columnist & Garden Designer
                                        AskMaryStone.com

More about the Podcast and Column:

Welcome to Garden Dilemmas, Delights, and Discoveries.

It's not only about gardens; it's about nature's inspirations, about grasping the glories of the world around us, gathering what we learned from mother nature, and carrying these lessons into our garden of life. So, let's jump in in the spirit of learning from each other. We have lots to talk about.

Thanks for tuning in, Mary Stone
Garden Dilemmas? AskMaryStone.com
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Transcript

Ep 204. Dividing Iris and Multiplying Gifts

Sat, May 03, 2025 4:43PM • 11:05

SUMMARY KEYWORDS

Garden dilemmas, dividing iris, native plants, perennials, hosta, daylilies, Rudbeckia fulgida, Siberian iris, Bearded iris, plant division, garden design, deer resistance, garden therapy, pass-along plants, garden memories.

SPEAKERS

Mary Stone

Mary Stone  00:00

Mary, Hello, fellow lovers of all things green. I'm Mary Stone, and welcome to garden dilemmas, delights and discoveries. It's not only about gardens. It's about nature's inspirations, about grasping the glories of the world around us, gathering what we learn from mother nature, and carrying these lessons into our garden of life. So let's jump in, the spirit of learning from each other, we have lots to talk about.

Mary Stone  00:23

Hello there. It's Mary Stone on a breezy screen porch. I've beat it out here before the peepers start singing. Actually, it cooled down quite a bit and such low humidity on this last of April day, I cannot believe we are entering May and time just unfolds, doesn't it? More rapidly than I would like, but when you think about life happening so fast, it makes it go faster. I'm really trying to just cherish every moment and not feel the rush of time, because you can do that and it just escapes you. So thank you for joining me, and I want to thank those that reach back after our last chat about Violet and Pansy Season of Happiness, this morning, I went out into the woods with Jolee for first call, and I saw one of those freckled faced Viola sororias, the native violets that we spoke about last time. And it made me happy, because I know I talked about freckled faced ones, and then I couldn't find any to photograph. So now I have one to add to the blog post. 

Mary Stone  01:27

So today we're going to talk about making more plants, dividing Iris specifically, and some gifted plant reflections. It was a highlight of my weekend, dividing and moving perennials, adding them to the garden around Ellie's Memorial Holly, I have construction pending removing the telephone pole retaining walls - finally. When I first moved here, I made a design for the area all around the house and other gardens, and I've pecked away at the list of my wishes, and that one has been one of those that just never got done. So, I am asking one of my dear associates, who's a very creative young man, to use the boulders in the woods and around the yard to create boulder walls instead of telephone poles. And I'm really looking forward to it. So, in preparation of Charles coming, I wanted to move some of the perennials that are there emerging because it's my favorite time to move plants, such as perennials, as we spoke about in episode 201.

Mary Stone  02:28

They say it's best to devise spring and summer blooming perennials in the fall and fall bloomers in the spring. That way all the plant energy can go into root and leaf development rather than flowering. But I always prefer to move perennials in the early spring, no matter when they bloom, although there are some exceptions, because plants are easy to move and maneuver around when they are just emerging, and their roots are full of energy and are less likely to suffer physical damage and leaf evaporation. 

Mary Stone  02:57

As I was dividing the hosta, I was thinking of Nancy the origin of many of them, other than the beefy, big-leaved one given to me by a client who didn't want to deal with the deer damage anymore. Hosta is indeed salad to deer, but the husky leaved ones seem to make out a little bit better until the feeding frenzy in the fall. It's fun to reflect on the origin of pass along plants. 

Mary Stone  03:23

I have Stelldora Daylillies, admittedly not my favorite, as they are overly used, but a neighbor had cast them away, and they were in a pile, all wilted and mushed together. So I offered to resurrect them, and they rebounded beautifully, spreading ambitiously. They're much like hosta, easy to divide, cutting apart their roots. And while they are not native, they provide a lot of bloom, and I have grown a fondness for them because of their resilience. There is a native alternative if we're going out to buy plants, and that is Rudbeckia fulgida - orange cone flowers, the common name or perennial Black-Eyed Susan. But why turn away plant divides that others give you if you have the garden space and they aren't harmful to the environment, that's my motto. But I do encourage folks to shoot for having 80% native plants, not holding it against plants that have been brought here ornamentally, as long as they are not invasive, as I said.

Mary Stone  04:22

Then came the iris that I needed to divide. I have some beautiful, white, fragrant ones given to me by my colleague and dear friend, Marty Carson, who I've spoken about many times. Her hip, by the way, is recovering, and she's doing fairly well, although there are some rapid changes I'm concerned about. I love her so much. She's taught me so many things in this garden of life, and we worked together for years developing planting plans and garden designs. Such a talented, lovely lady. In her stash was a surprise purple and white iris and a maroon one that I adore in the rock garden. I also have some existing Siberian Iris that came with the house. It's time to divide them a subject for this week's story that starts like this. 

Mary Stone  05:10

Hello, fellow lovers of all things green. I look forward to when the Siberian Iris planted by the previous owner emerge in the rock garden and flourishes with deep purple flowers in late spring or early summer. But they have not had nearly as many blooms in the last few years. The same is true of their fragrant white Bearded Iris, Iris Germanica, handed down to me by my dear friend. Yes, dividing them is long overdue. Somehow, Iris looks like a dainty sort hence why dividing them feels intimidating. In comparison, hosta are easy to divide using a small ax to hack the roots apart, or a gardening knife, which sounds a tad violent, perhaps, but hosta are quick to recover and are very tough plants. Bambi loves them, though, so the rotation of my two favorite natural deer sprays deer out and deer off, keeps them away. While Iris are deer resistant, the buds can get nibbled from time to time, so it's best to spray them too. 

Mary Stone  06:11

The best time to divide Iris depends on the kind of iris, and it's not that difficult. So please don't let the following recipe intimidate you. The method is the same for all irises to maintain plant vigor and prevent overcrowding. Bearded Iris are best divided every three to five years. The same is true of our native Blue Flag Iris, Iris Versicolor which has similar sword like leaves, they have a daintier blue violet flower in various shades, with lovely veins and pale yellow highlights. The best time to divide them is in late July through August, so as not to miss out on the spring blooms. Yay. I'm off the hook for now. 

Mary Stone  06:52

So here's the recipe: After cutting back the leaves to a third of their height, dig up a clump, then wash off the dirt from the underground stems called rhizomes, pull them apart by hand or use a sharp knife, ensuring each division has large, firm rhizomes and two to four fans of leaves with each clump. There's an iris borer. It's a stealth little pink caterpillar that feeds on the insides of rhizomes, and it often leads to bacterial soft rot. So, squeeze those roots, even if they look okay from the outside, to make sure they are solid, and plant the divides right away. 

Mary Stone  07:29

Dig holes the size to accommodate each split, typically about five inches wide and deep, spacing them 16 to 18 inches apart, and create a mound of soil in the middle. Sit the rhizome on the mound and spread out the roots. Irises prefer full sun and well-drained soil, so add compost to clay soil. Each rhizome should be just below the surface after you cover it with soil, water them thoroughly and avoid adding mulch on top, as that can retain moisture and encourage rot. 

Mary Stone  08:00

I think the narrow grass, like leaves of the Siberian Iris, Iris siberica, are more appealing in the garden after flowers are spent, than the sword-like foliage of Bearded Iris. But both are beautiful and bloom. Siberian irises don't need dividing as often as Bearded Iris. Another plus, not that I'm lazy. Well, I am kind of when it comes to these kinds of tasks. Although I love making more plants out of plants. It's so fun. When they bloom less have their centers and become crowded like mine. It's time. It's the same technique as the bearded cousins, though they are deeper rooted. The best time in colder zones such as ours and I'm a zone 5b or six is early spring when the foliage emerges, and the second-best time is late summer. But no more procrastinating, Mary, just get out there and do it. And I did. I did. I got to it. Made more plants. 

Mary Stone  08:54

Besides dividing Siberian Iris takes some muscle to excavate their deep roots, you may need to bring out your garden spade and jump on it like a pogo stick we spoke about before. Jump around the outside of your clump before digging it out. But hey, it's good exercise, and being outside is an excellent form of therapy, plus how fun to make more plants, especially when you share them with your friends and neighbors. Garden dilemmas, askmarystone.com.

Mary Stone  09:22

So, I'd love to hear about plants that were given to you and about the special people that shared them so generously. I know I did a story a while ago about the history of house plants and all the memories they brought to me, and it kind of was like that when I was out there moving things. And it's fun to do reflect on those beautiful gifts that we pass forward. 

Mary Stone  09:47

So while I was out there dividing plants, I was doing my fair share of sneezing. It is true that the flowering trees are spewing out their yellow pollen, causing my itchy eyes and having to take an allergy pill, but I'm not complaining. It's a constant cycle, and it's a beautiful thing. So, deal with your itchy eyes and your sneezing and realize that it's part of the new beginning of the growth that's occurring in our lives and in our hearts and amongst each other. So, thank you for this time together. I always enjoy it, and I love hearing your stories. So, tell me about your plants gifted to you, or any other Garden of Life story or nature story you'd like to share. You can email me at Ask Mary stone@gmail.com. Until the next time, enjoy the beautiful day. 

Mary Stone  10:35

You can follow garden dilemmas on Facebook or online at Garden dilemmas.com and on Instagram at hashtag Mary Elaine Stone. Garden dilemmas, delights and discoveries is produced by Alex Bartling. Thanks for coming by. I look forward to chatting again from my screen porch and always remember to embrace the unexpected in this garden of life. Have a great day.