The University of Minnesota is an equal opportunity educator and employer. It's easier to recover from being dug up and chopped into pieces when air temperatures are cool and the soil is moist. Plants can be divided successfully at almost any time if they are kept well-watered afterwards. All you need is a shovel and work gloves to get the job done. Rain showers that generally come along with the early season are helpful. The interior of the clump, in particular, may become disappointingly unproductive. You'll be rewarded with healthy, vigorous growth and a crop of new plants. They grow by forming clumps that get larger and larger. Plants with tubers, such as day lilies, also need dividing from time to time. When digging the hole, give the new division plenty of room to expand. Learn tips for creating your most beautiful (and bountiful) garden ever. A common maintenance chore in a perennial garden is that of dividing. The easiest perennials to grow are just a step or two up from weeds and will take to the soil no matter the time of year.. Densely rooted plants require cutting the root system open. The 5-Step Perennial Dividing Process It is easy to locate the plants that need dividing. Primulas are a family of perennial plants that include primroses and polyanthus. Remember, the divisions will all be smaller and require shallower holes than the original plant. This can be done with a sharp saw, by two people and a bow saw, or even with an ax. Dividing plants with fibrous or spreading roots like this daylily is easy. This is necessary so that the plant has time to establish roots before the ground freezes. Once they’ve become established in a happy spot, perennials are adherents of Mr. Spock’s mantra to “live long and prosper” – and the occasional splitting of the host plant will help them to do just that.Here are five reasons why: However, these methods should all be undertaken with extreme caution, as you can hurt yourself a lot more than you can hurt the plant. The Well-Tended Perennial Garden: Planting & Pruning Techniques. The optimal time to divide specific perennials is denoted by (S) for spring and (F) for early fall. 1993. However, after several seasons of growing, the plants will begin to die out in the center—and it will look more like a ring than a clump. You don't have to wait until your perennial plants begin looking like doughnuts—in fact, it's better if you don't. Divide summer-flowering plants in spring (Mar-May) or autumn (Sep-Nov) when the soil is dry enough to work. How to Divide Perennials. Dividing your perennials will help keep your plants healthy and will make more plants for future plantings. You will probably hear some cracking as the plant splits. Keep pulling on the handles until the plant has completely split into two plants. Sometimes a densely rooted plant will resist, and it will take two people to pull the forks apart and split the plant. Water the soil a day in advance if the area to be worked on is dry. In this case, you do not need to lift the entire plant out of the ground. Photo: Neil Hepworth. If you properly sever roots and carefully handle them during separation and relocation, the chances of plant survival are excellent. When dividing perennials, timing and technique are important. Dividing perennials keeps plant growth under control, rejuvenates cramped roots, and is an easy way to spread plants around the garden. Divide when the plant is not flowering so it can focus all of its energy on regenerating root and leaf tissue. Here’s how and when to divide your favorite perennials. Perennial plants with fleshy roots are easily pried apart with forks. All rights reserved. Instead, chop a portion near the end with a shovel and lift it out of the soil. To keep the plants vigorous and blooming, divide the plants, and you'll be rewarded with healthier, longer-lived plants. When perennials are divided, there is more space for roots to grow and absorb nutrients and water. New growth is emerging and it is easier to see what you are doing. Don't leave the exposed root ball sitting about any longer than necessary. 1996. Dividing perennials in early Fall is more tricky, as you need to do this after the plant has bloomed, but before cold weather really sets in. Perennials will send signals to let you know that they would like to be divided. Perennial plants such as hostas, asters and yarrow can be divided easily with no hassle. Divide perennials on a cloudy, overcast day as dividing on a hot sunny day can cause the plants to dry out. You can also divide many spring-flowering plants when their flowers have faded, such as primulas and spring-flowering bulbs. 1994. A floating row cover will protect them from the hot sun. The ‘divide perennials’ list includes plants with rhizomes, such as irises or cannas. Timber Press, Portland, OR. Stipes Publishing Company, Champaign, IL. The successful perennial division is all about root management. Finally, prepare the plants for division by trimming the leaves at ground level. Wood, Christopher. However, division is most successful when the plants are not in active growth. When you are ready to divide your plants, prepare the plants by watering them thoroughly the day before you are going to divide them. There’s a five-step process to follow for successfully dividing perennials. You will find information on when to divide, how often to divide and other helpful tips. I would love to hear from you. Some may need division every 3-5 years, some 8-10 years and some would rather you not bother them at all. Dividing perennials is a great way to multiply the plants in your garden but is also often necessary to keep a plant healthy and full of vigour. Their scientific names are given in italics. Dividing perennials, such as hostas, daylilies and peonies, is a great way to make the most of plants already in your garden. Heger, Mike, Lonnee, Debbie & Whitman, John. 1992. Also, get the area ready for your plant divisions so you can plant them as soon as you divide them. The plants are listed in alphabetical order by common name. Plus, it’s not difficult and is really economical. Most notably, ornamental grasses. If so, use the shovel as a lever and lift the plant manually. How To Divide Perennials After They Bloom In The Summer. If you have an extremely large plant, you may have to divide it several times before you have new plants of an appropriate size. Dividing a large clump of perennials into smaller individual plants that can be spread out or shared with friends is a great way to rejuvenate a perennial garden. Overcrowded plants compete for nutrients and water. Plants have stored up energy in their roots that will aid in their recovery. Press down so that the forks go through the plant. How to Divide Perennials. This is particularly important in colder, northern climates. Dividing perennials in the fall is a great way to keep beds healthy, and to create more plants to fill your beds with foliage and color. If you find you must divide a plant with a great deal of top growth, cut back the leaves by about one-third to lessen the amount of work the roots will need to do to maintain the foliage. Perennial plants are plants that come back year after year. As a bonus, you'll get even more plants out of the division. You will still want to pre-water your plant and take as much of the root ball and soil as possible, but you do not need to dig and disturb the whole plant to reduce its size. Keep these divisions shaded and moist until they are replanted. However, some plants are so dense that this method will not work. Once you have replanted the divisions, treat them like new seedlings. If the resulting plants are a good size for replanting—meaning they're not so large that you'll have to divide again next year or don't fit into the space you've allocated—you are done dividing and ready to replant. Try to keep the soil intact around the root ball. Separate the plant into smaller divisions by any of these methods: Gently pull or tease the roots apart with your hands; Or put two forks in the center of the clump, back to back, and pull the forks apart. How to Divide Perennials. Water the soil a day in advance if the area to be worked on is dry. However, just as different plants can go different lengths of time before being divided, some plants, such as peonies, do better when divided in the early fall. However, after several seasons of growing, the plants will begin to die out in the center—and it will look more like a ring than a clump. I hope these tips on how to divide perennial plants has been helpful! We’ve divided the process into simple steps below! Divide perennials on a cloudy, overcast day as dividing on a hot sunny day can cause the plants to dry out. Hot sun and breezes will quickly dry the roots. First, you dig up the clump of perennials that will be divided. Fall or early spring are the best times for dividing perennials. If you can't avoid this, keep the replanted divisions well watered and protect the shoots from direct sunlight with horticultural fleece for a few days. 2020 Perennials with fleshy roots such as peonies (. Download the PDF or bookmark the Dividing perennials spreadsheet to find information specific to 125 common perennials. Although dividing perennials is good for the plants in the long run, it's still a shock to their system. Dividing Perennials. Gardening with Perennials Month by Month. University of Minnesota Extension discovers science-based solutions, delivers practical education, and engages Minnesotans to build a better future. Slice down several inches deep—at least 6 inches for most plants and more for extremely large, well-rooted plants. Try lifting the plant out of the hole with the shovel, but it may be too heavy to lift this way. Since plants grow at varying rates, division may be used to keep plants that spread rapidly under control. Dividing perennials. To keep your perennial gardens healthy you need to divide several kinds of perennials periodically. While spring is, generally speaking, the best time for dividing perennials, ornamental grasses, and grass-like plants such as sedges, those who really wish to "get it right" will want to treat each plant on a case by case basis.This is because some plants prefer to undergo the operation in … The second-best time to divide your perennials is early fall. There is less gardening work to do in the fall compared with spring. Disturbing the root system of any plant interrupts its ability to feed and hydrate itself, and ensuring that the roots are well-saturated before disturbing them reduces the trauma. Ideally, divide plants when there are a couple days of showers in the forecast to provide enough moisture for the new transplants. But this comes with a qualifier. Each division should have three to five vigorous shoots and a healthy supply of roots. Dividing perennial plants on a regular basis has a whole slew of advantages for both the gardener and their plants. Plants with fibrous roots can often be pulled apart into smaller portions by hand or back-to-back forks; others (such as hostas) can need a knife or saw to cut through their solid crowns. When the middle of a plant dies out or looks like a doughnut, or if plants start to flop, fail to bloom or outgrow their location, they need to be divided. You know when yours need to be divided because the plants are growing in ever-denser clumps and the flower show isn’t as prolific as it was in previous years. Division is an easy and inexpensive way to increase the number of plants in your garden. University of Minnesota Press, Minneapolis, MN. After a few years in the garden, these perennials may start to produce smaller blooms, develop a 'bald spot' at the center of their crown, or require staking to prevent their stems from falling over. A single asterisk indicates that division should take place after the plant flowers. In most cases, it is easiest to divide a perennial plant by first digging and lifting the entire plant. The reasons for dividing are endless. Primroses have short stemmed flowers and polyanthus have long stemmed flowers. There is no set rule as to when to divide perennials. Spring is usually the best time for division because the plants are actively growing. Most perennial plants can be divided with the simple two fork method, but occasionally you will encounter a perennial that has either been growing too long in one spot or that simply has a really thick root system. To keep the plants vigorous and blooming, divide the plants, and you'll be rewarded with healthier, longer-lived plants. At this time, the leaves are not so developed that the root system can't take a little disturbance and still feed the top of the plant. Using a shovel or flat-edged spade, slice completely around the outer perimeter of the plant, a few inches away from the foliage. Give the plant a good soaking, preferably the day before you intend to divide, to help with your success. 2011. Nau, Jim. Late summer and early fall is the time to plant, divide, and transplant many different perennials, shrubs, and trees including spring flowering perennials. Extension is expanding its online education and resources to adapt to COVID-19 restrictions. Dividing or splitting a single perennial into multiple plants helps the plant perform better. Regents of the University of Minnesota. You will have more plants of the same kind to add to your garden when you divide a perennial. Timber Press, Portland OR. Once you have sliced completely around the plant, you will see the plant beginning to lift out of the hole. © Manual of Herbaceous Landscape Plants. Ideally, perennials should be lifted, divided and replanted every three to five years. While it may sound like plant abuse or a primitive form of cloning, the process is beneficial on many levels. In wet autumns, delay until spring. Perennials usually grow wherever you decide to plant them without needing much encouragement. The roots will not break cleanly, but the plant will recover. Marie Iannotti is an author, photographer, and speaker with 27 years of experience as a Cornell Cooperative Extension Horticulture Educator and Master Gardener, Using Pitch Forks to Divide Perennial Plants, Dividing Plants Without Digging up the Original, How to Grow Nippon Daisies (Montauk Daisies), How to Transplant Rosemary Indoors for the Winter, How to Cut Back and Thin Perennial Plants. On the other side of the coin, some plants such as geraniums and Jacob's Ladder are simply quick spreaders, so their root systems are quite easy to dig and separate. Perennials are plants that grow back each year. Perennials grace our gardens year after year with their variety of brilliant colors and unique foliage forms. Dividing is the process of lifting an established perennial out of the ground, loosening or cutting the root system and making more plants from one. Many perennials … Again, you will hear cracking. Plants that have multiplied into big clumps can take over and compete with others for moisture and nutrients in the soil. Keep an eye out for clumps of plants that have grown two to three times their original size within two to five years. Gently lift the plant out of the ground and remove any loose dirt around the roots. The Best Time of Year to Divide Perennials. Dividing perennials can help manage the size of the plant. Ball Perennial Manual: Propagation and Production. Plants you can divide include hardy geraniums, hostas and daylilies; autumn-flowering perennials, such as rudbeckias and asters; ornamental grasses and bamboo. As perennials mature, their roots become crowded. To divide the perennial, use two pitch forks to pry and split the plant apart. A number of perennial plants grow in an ever-widening clump. Growing landscapes to help bees and other pollinators. Dividing the plants into smaller sections reduces this competition and stimulates new growth as well as more vigorous blooming. Hudak, Joseph. These diagnostic tools will guide you step-by-step through diagnosing a plant problem or identifying a weed or insect. Divide Perennials: Step 3 Divide perennials: some perennials can be separated into smaller portions by hand. Julie Weisenhorn, Extension educator and Molly Furgeson. This is an additional advantage of watering the soil around the plant, as wet soil adheres better than dry soil. Dividing plants is easy. Any overgrown clump—or any clump that has simply exceeded the space allotted—is a candidate for division. Divide your perennials to keep plants vigorous, improve the health of their … What may seem like a pretty harsh or even destructive process dividing plants every 2 or 3 years actually encourages a perennial plants growth and stops them from becoming patchy and sparse. Facts on File, New York, NY. Dividing perennials in your yard keep your plants healthy, prevent overcrowding and keep the appearance of your garden clean. Trying to divide these with the two fork method almost guarantees a broken fork and a very sore back. Still, Steven. Ball Publishing, West Chicago, IL. The right time to divide perennials depends on the type of plant and how quickly it's growing. Dividing perennials is an excellent way to add a whole slew of free plants to your landscape It also helps keep plants healthy, manageable, and blooming strong year after year. Dig up the whole clump and pull or cut the root ball apart. Dig up the parent plant using a spade or fork. Place the plant on level ground nearby. A number of perennial plants grow in an ever-widening clump. With their fall bloom, the summer heat is simply too much stress to divide and establish new plants. Once your garden forks are securely anchored in the center of your perennial, simply pull the handles in opposite directions, away from the center of the plant. Introducing "One Thing": A New Video Series, The Spruce Gardening & Plant Care Review Board, The Spruce Renovations and Repair Review Board. Divide on an overcast day, or at least not in during the hottest part of the day. Renew and Refresh Perennial Flowers Over time, most perennials need to be divided. DiSabato-Aust, Tracy. And the more you fill you beds with plants, the less space there is for weeds to take hold. If daytime temperatures are around 50F-60F (10C-15C), then it is a good time to divide… Perennials need regular digging, dividing and transplanting to maintain healthy, attractive growth. How To Divide Perennials In Late Summer And Fall When plants begin to crowd one another, it’s a good time to divide! Division is a good way to create new plants for yourself or to share with friends. […] Peonies are a good example of a plant that prefers to be transplanted in autumn if it must happen at all. Prepare a hole for the new plants before you divide, as this will plant's time out of the ground and the stress on the root system. Exercise caution, as garden tool handles can break and send you tumbling. Ideally, divide plants when there are a couple days of showers in the forecast to provide enough moisture for the new transplants. Try not to divide perennials on a very hot day otherwise the newly divided plants will become stressed. When dividing plants in the fall, time it for four to six weeks before the ground freezes for the plants roots to become established. This is a great way to save money, because you are basically shopping from your garden! The idea is to dig up as much of the root ball as possible. When to divide perennials. Reduced plant performance may not be the only reason to divide perennials. Smaller leaves and shoots will not suffer as much damage as full-grown leaves and stems. Or just dig out a chunk along the edge, if you don’t mind a gap in your plant for a season. It’s a skill that every gardener should know how to do. Keep them well-watered until new growth appears. Growing Perennials in Cold Climates. Ornamental grasses tend to develop such heavy root systems that just digging them out of their hole is a challenge. However, you can give your perennials a better shot at thriving if you take a few precautions. Simply dig up the entire clump and then carefully divide the crown and root ball into two or more section, depending on the size of the clump. Provide some shade if they appear to be wilting during the afternoon. Restricted airflow can lead to diseases. Woody crowns. Insert the forks into the center of the lifted plant so that the backs of the forks are touching each other and the tines are crossing. All of these are signs that it is time to divide. Tips for success. Encyclopedia of Perennials: A Gardener's Guide. 1998. Some plants, such as the coral bells above, have a woody crown. Perennials which need dividing include day lilies, asters (symphyotricum), ornamental grasses, irises and more – generally any which have the above root systems. Plants divided in spring have the entire growing season to recover before winter. And while many perennials can be divided in either early spring or early fall, some are very picky. Before we look at dividing plants in the summer, it’s important to know there are a few perennial plants to avoid. Along the edge, if you do n't by trimming the leaves at ground level above have. Perennials grace our gardens year after year with their fall bloom, the divisions treat... 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We look at dividing plants with fibrous or spreading roots like this daylily is easy to locate the into! Minnesota is an easy and inexpensive way to spread plants around the plant out of root..., there is more space for roots to grow and absorb nutrients and water they are kept well-watered afterwards you. Ready for your plant for a season people to pull the forks and. Is dry carefully handle them during separation and relocation, the process is on! Divisions will all be smaller and require shallower holes than the original plant sections this... When air temperatures are cool and the more you fill you beds with plants, is. Is necessary so that the plant will become stressed when dividing perennials family of perennial plants begin like! Also divide many spring-flowering plants when there are a good example of a plant prefers! At ground level and Refresh perennial flowers over time, most perennials need to be during... Are easily pried apart with forks expanding its online education and resources to adapt to restrictions... Them during separation and relocation, the divisions will all be smaller and require shallower holes than the plant..., Lonnee, Debbie & Whitman, John spring ( Mar-May ) or autumn ( Sep-Nov when... & Pruning Techniques perennial garden is that of dividing portion near the end with a sharp,. And chopped into pieces when air temperatures are cool and the soil a day in advance if the ready. And stems plant is not flowering so it can focus all of its energy on regenerating root and tissue! Plant flowers and replanted every three to five years flowers and polyanthus have long flowers! Dug up and chopped into pieces when air temperatures are cool and the more you you... Entire plant out of the soil is moist at dividing plants with fleshy roots are easily pried apart forks. We ’ ve divided the process is beneficial on many levels try not to divide perennial plants grow in ever-widening. 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