Newer Post, © Copyright 2021 DutchGrown. Irises can become congested over time, which tends to inhibit flowering. Should have thought of that first. Once the holes are dug, place the rhizome into the space. All of my irises came from the gardens of family and friends, so they are precious to me and I don’t want to lose them due to my neglect. With the heat, humidity and mosquitoes of August you many not feel like working in the garden at this time of year, but a little time spent dividing crowded clumps of bearded iris now will pay great dividends in the future. Steps to dividing your bearded irises Using a shovel, dig up entire clump. Submitted by Mike on September 4, 2020 - 10:40pm. Bearded irises are tall, elegant additions to the flower border, but they are also relatively high maintenance. I left the rhizomes showing a bit, in full sun; they are more closley planted than you recommended, and have multiplied. Division differs slightly. How: 1) Dig up the entire clump with a garden fork or split off individual rhizomes. How is the soil? This year, I made a mental note that I should divide and replant the irises after flowering. Often it just takes a few years for the plants to overcome the shock of being transplanted and to adjust to their new digs. This can be remedied by lifting and dividing their rhizomes to give them a little more space. Submitted by Carolyn T Fields on September 1, 2019 - 1:14pm. Buy It: Tall Bearded Iris, from $14, White Flower Farm. Rhizomatous types include bearded, Siberian and Japanese irises. Put them all on tarps - lots of dirt, easier to clean up. Is the top of the rhizome near the surface of the soil? It's similar, but I didn't get small, tidy, individual stalks to replant. Being a lazy gardener myself, I’d give them another year before moving them to a new location. Of course, that's just a cautionary message from a middle age dude! In climates with hot summers, plant the rhizome just below the soil surface. How to Divide Bearded Iris Bearded iris grows from a thick, rootlike structure called a rhizome. Iris loves the heat and drier weather of summer and the summer dividing will reduce the incidence of bacterial soft rot. Robin has been a contributor to The Old Farmer’s Almanac and the All-Seasons Garden Guide for many years. The Siberians don't seem to "have their toes hanging out", the way the bearded ones do. Thanks for the (very timely!) The foliage is looking good, though. Bearded iris need to be lifted and divided every 3 years or so anyway (this is usually done after flowering). Are the other plants shading them more than you realize? Plant the iris bulbs in holes four inches deep and about ten inches apart. Discover our iris collection, with a range of Dutch iris and dwarf iris in colors to suit every planting scheme. How to divide irises and replant them in the garden. Generally, iris plants are divided every three to five years. Do NOT divide in the spring. The stems can also be solid, hollow, flattened or in a circular cross-section. Noticed someone asked about dividing those. How to Divide Bearded Irises Dig the rhizomes up and check them for disease or insect damage. In addition, plants are less likely to produce any blooms. The best time to divide iris is in early fall: Many gardeners treat Dutch irises as annual plants, discarding the old bulbs and planting fresh ones each fall. We found some borer damage and mushy rhizomes that we discarded. After blooming, cut off the stem but leave the foliage through summer. I have Siberian irises. Division of bearded iris plants and siberian iris rhizomes or bulbs is not a difficult task for any gardener provided you have the right tools. As the plant matures, the rhizome multiplies, which in turn lead to more leaves and flowers. However, given a sunny, well-drained spot they will rebloom and will eventually need dividing. Many gardeners treat Dutch irises as annual plants, discarding the old bulbs and planting fresh ones each fall. Thanks for your assistance! Learn when to divide iris bulbs for the best results. However, if the center of the clump stops growing, it’s time to divide the plant. Plant rhizomes singly or in groups of three, 1 to 2 feet apart, depending on the size. Late summer is the perfect time to divide or thin your iris. The bed they are in is narrow and next to large rocks leaving the irises nowhere to go. See the Almanac’s Iris Growing Guide. This article applies to the bearded iris. Learn more about growing iris. Bulbous irises form a more typical bulb which includes the Dutch iris and are planted in the fall with other bulbs. They are long and firm with multiple growing points over the surface. Thank you! Choose the right time of year to divide. Leave the foliage over the summer until it dies back naturally in fall, then dig up the Dutch iris bulbs, discard any damaged ones and replant them in a new location. Plant iris rhizomes so the root end is on the bottom, covering with soil until just the top is exposed. Cut back the leaves to 1/3 their original height. When to divide irises Rhizomatous irises (having fleshy stems at soil level) are divided just after flowering Clump forming irises are divided in early autumn or early spring If you are looking for an easy flower to grow to create a border along your house or need to fill up a flower bed quickly, then irises may be a flower to consider. At least it's something that only has to be done every 3 to 5 years! Know your iris. They look lovely combined with other spring flower bulbs in beds and containers and will also naturalize in clumps when planted in grass. However, for larger varieties of iris plants, you’ll want to go with a larger distance than two feet. An iris is a flower that grows from creeping rhizomes and — in some dry climates — from bulbs. The best time to plant and transplant rhizomatous iris is late July through September. These plants do best when divided every few years, and the process is really quite simple. We had enough leftover rhizomes to plant another bed on the other side of the stone wall. They are perennial and will bloom for several seasons. Custom programming and server maintenance by. When your irises become overcrowded, its time to divide and transplant iris tubers. This not only alleviates issues with overcrowding but also improves their overall health. The word "bulb" can be a bit confusing when applied to an iris. I planted irises about a year and a half ago, in zone 7a -- Montgomery, AL. Steps for Dividing Iris Plants. Do they like it drier? Irises are one of the easiest spring flower bulbs to grow, bringing glowing color to your beds, borders, and containers in spring. Flower Bulbs from our family farm in Holland. But dividing bearded irises every three to five years allows the clump to rejuvenate and bloom better (not to mention a way to multiply your irises to fill in gap). Increasing means make new rhizomes you can divide out later for more Iris. The best time to divide Siberian iris is in summer, after blooming. Do I follow the same steps as for the bearded irises? or read more about me. You can help cut down on the incidence of soft rot and borer damage through the regular division of the iris rhizomes, every 2 to 3 years. Weeks to feel better. Or should they? I need to move mine and didn't know this was actually perfect timing. Big chore. If the iris bed is producing plenty of green foliage but very few blooms, it's a sign that the iris rhizomes have become crowded, and it's time to divide. Use a spade or fork to dig up the iris plant. Watering the iris for two days before dividing makes the soil easier to dig. Siberian irises form large clumps of grass-like leaves and enjoy cool, damp conditions. Split iris between late July and the end of September, and use the divisions to start a new iris bed, or give them away to family and friends. I hurt my shoulder badly. Steps 1. If possible, lift the whole mass out whole, but if you are unable to do this, carefully break the clump into smaller parts and lift these out. The best time for division of bearded irises is post flowering, at which... 2. If you’re wondering if now is the time to divide your rhizomes, look for these cues: The plant is … If planted too deeply they won’t flower. BONUS: You’ll also receive our Almanac Companion newsletter! It’s important to divide and replant at the right time of year. We found some borer damage and mushy rhizomes that we discarded. Dig the rhizomes up and check them for disease or insect damage. Dig up the rhizome clumps and cut apart with a sharp knife at the visible seams. The bearded iris falls into this group. Dig a shallow hole 10 inches in diameter and 4 inches deep. It is easier on your back. Ugh. You can probably get away with dividing through mid-September. If your irises are suddenly blooming less than in past years, it is likely time to divide them. Cooler maritime weather areas will find that transplanting right after bloom will get the plants back to … Once established, bearded irises are drought-tolerant and won’t need additional watering. The roots are quite long and will help anchor the newly planted rhizome in place. Water the area well after planting. How to Divide Dutch Irises? I'm feeling confident that they'll come back next year with a nice bloom. Too much nitrogen will foster lush growth at the expense of flowers. The first spring, however, this year, only two flowers showed up after all that stress. Submitted by Robin Sweetser on September 10, 2019 - 3:02pm. Submitted by El on September 4, 2020 - 7:29am. After 5 years, they slowed blooming and I could see the center was dead, an outer ring still green = time to divide. In many regions, July through August is the best time to dig, divide and transplant bearded irises. The Process of Dividing the Iris Plant Rhizomes. To divide your iris, start by lifting the clump of iris plants out of the ground with a spade or fork. Each had to weigh 40 pounds by the time I got them out, loaded with soil in the roots, etc. Submitted by Monica Frame on August 26, 2019 - 9:37am. Try to avoid damaging the roots or the leaves. I only had 3 of them. Wait until flowering is over before dividing the iris clump, discarding any old, woody rhizomes and replanting only young, healthy plants into freshly-prepared soil. As the years progress both the number of rhizomes and their size increase producing a mass of rhizomes on the surface that needs to be divided. Older Post Then replant. Replant the newly divided rhizomes in a sunny well-drained soil. Using a knife or your hands, begin to break the rhizomes apart in groups of one to three. There are many reasons why irises don’t bloom but it sounds like yours have adequate sunlight and enough water. I leave at least 12 inches so they new Iris can grow and increase. Snap or cut off the old part of the rhizome since it will not flower again. Shake the dirt off as much as you can. A good rule of thumb for planting Iris in groups is 6 to 12 inches apart. How to divide summer bulbs- Cannas, Iris & more. Thank you! Irises that are grown from bulbs are not suitable for division. article on dividing and replanting bearded irises. Bulbous irises form a more typical bulb and include Dutch and reticulate iris. When plants are too crowded, they are more susceptible to diseases like bacterial soft rot. All rights reserved. Trim the foliage back to about 5 inches and shorten the roots if needed. They have a long and erect flowering stem that can be simple or branched. However, given a sunny, well-drained spot they will rebloom and will eventually need dividing. Leave the foliage over the summer until it dies back naturally in fall, then dig up the Dutch iris bulbs, discard any damaged ones and replant them in a new location. Now that you know how to divide iris bulbs, are you inspired to add some beautiful iris to your spring garden? Know when to divide the rhizomes. I am moving in the near future and want to take my Irises with me as they were also gifts, I wasn't sure how to go about it, but now I'm a lot more confident about tackling the project. Divide after the last frost or six weeks after the last bloom. It's important to know which irises you are seeking to divide. They have not bloomed. When To Plant For best results, plant iris rhizomes in July, August or September. The strappy leaves seem healthy but it is a bed with other plans (shrubs and perennials) that need more water than is suggested here. Next, brush of as much dirt as possible from the iris rhizomes. The best time to divide irises is during late summer, usually anytime between July and th… Next season’s plant emerges from the fan end of the rhizome so when replanting, face it in the direction you want plant growth to travel. Dig and divide your plants every 3 to 4 years to maintain plant vigor. Even though bare rhizomes can survive out of the ground for 1 to 2 weeks without any damage, it is best to replant them right away. Not sure if I should dig them up and plant on the west side of a north-south run of privacy fencing, where they would get almost all day full sun; they are currently opposite, on the east side of a north-south fencing, getting morning and until 2 pm sun. Even though my irises were planted years ago and are terribly overgrown, the blossoms were still gorgeous this spring. Get inspired by Robin Sweetser’s backyard gardening tips and tricks. Dividing plants with rhizomes, such as the beareded iris, helps them perform their best, and bearded iris usually need to be divided about every 3 or 4 years. The irises are getting crowded and encroached upon by sedum. This will also keep bearded iris performing and blooming at its best. Here’s how to divide irises—with step-by-step pictures. Water well to settle the soil around the roots and continue to water deeply once a week until new growth appears. This is also the best time (plants are normally dormant during the heat of July and August) to divide and replant iris that have become overcrowded, usually after three to five years. Bearded irises grow from thick, underground stems called rhizomes. 2) Remove excess dirt and dead material from the clump. Next spring we should have twice the blossoms! Send me your questions! Irises that grow from rhizomes (underground stems that produce both top growth and roots) should be divided every 3 to 5 years. Given that division can differ slightly between irises, it is important to know which irises you are... 3. Divide clumps of bearded iris plants every three to four years in late summer. Identify any diseased rhizomes, and lay those out separately. Dig up the clump and separate it into several sections, then replant them about 1” deep in soil enriched with compost. But seriously, be very cautious dividing irises or hostas or any well established perennial. Also, it’s helpful to avoid the iris borer which is a very destructive pest typically attracted to older, over-crowded gardens. Just no blooms. The content of this field is kept private and will not be shown publicly. My goal was to rework the iris beds, add some compost, get rid of the invading sedums and tree roots, and divide and replant the crowded rhizomes. I should have grabbed that saw first thing. Replanting Iris after dividing. Lift the plant carefully so you don't damage the rhizomes. DutchGrown LLC, 827 Lincoln Ave. Unit 8, West Chester, PA 19380, Signup to receive our latest news and hottest promotions. Dividing Iris bulbs All rhizomatous iris and true bulb types require dividing eventually to ensure strong growth as well as allow plants to multiply. These are planted in October with other bulbs. I also have Siberian Irises, which should be divided because their patch is becoming crowded. Keep reading to learn more about replanting bearded irises. Some Irises (ones that grow like a clump of grass), can be lifted and divided up with a sharp knife or spade. When the leaves die back in fall, dig up the bulbs and separate them before replanting in a sunny spot. Pinched a nerve. Crowded plants are also more prone to disease problems. Submitted by Ashley on July 8, 2020 - 9:01am. Carefully dig up the iris clumps with a spade. In Iowa, July or August is the best time to dig, divide, and transplant bearded irises. Wonderful guide to dividing and caring for Bearded Irises, thank you for sharing! It was sweaty work, even on a cool day, but so rewarding to see it done. She and her partner Tom have a small greenhouse business and also sell plants, cut flowers, and vegetables at their local Farmer’s Market. Choose the correct time to divide the rhizomes of the dwarf iris. The blooming of the bearded irises is something I eagerly await each spring. Ensure the rhizome is erect while the roots are spread out. Replant the largest and healthiest-looking rhizomes. Amend the soil with compost and dig a shallow hole or trench. Fertilize early in spring and again right after blossoming with compost or a low nitrogen fertilizer. Replanted the vigorous growth, dumped the dry, had lots for the back yard and front. To thin, cut the leaf blades back to about 4 to 6 inches in length. You must do this job post flowering, during the summer. That time is now! If left undivided, the flowering will decrease and the rhizome will be subject to more pests and damage. It is easier to plant if you cut the tops back to about 6 inches tall. The Best Time to Separate Iris Bulbs. If you want to know how to divide Iris then you can read all about that here. Snap or cut off the old part of the rhizome since it will not flower again. It worked. Space the pieces 12 to 24 inches apart for tall types, closer for dwarf ones. I planted mine closer, for a more immediate display, knowing that I will have to divide them again sooner. Divide irises during the summer … Loosen around the clump as best you can. Make a mound of soil in the middle to place the rhizome on, spread the roots out over the mound and cover them with soil. When dividing, cut back ¾ of the foliage and plant large single or 2 to 4 fans, removing the old rhizomes and roots. Irises like a near neutral pH and even amounts of nitrogen, phosphorus, and potassium. Iris, cannas and rhizomes all look rather like sweet potatoes. Dwarf irises, with their royal blue blooms supported on short stems, bring a bold splash of color to the garden in early spring. Dig up Iris Rhizomes Start a good 5 to 6 inches back from the base of the Iris clump and dig in your shovel or garden fork. When replanting, bury only the “root end” and don’t cover the larger section of the iris. For bare-root irises, plant the rhizome horizontally with the top exposed. How to divide iris: Step-by-step instructions Dividing Iris Why: Division every 3-4 years is important for continual bloom and vigorous and healthy plant growth. Tried different methods to separate clumps and get rid of the dead areas and after failing and struggling many times, I settled on a handsaw! As irises mature, the rhizome produces more rhizomes. This is hot, heavy work involving a lot of digging so I waited until the weather cooled down a tad before starting. Since they are in a bed with other plants, is there too much root competition?