Spring is a great time to divide many of our favorite herbaceous garden perennials. The plants are small, easy to handle and they have the entire growing season to get re-established in your garden. But how do you know how often to divide perennials? Are there some perennials you just shouldn’t divide?
The term “perennial” literally means to last or exist for a long time and to be enduring or continually recurring. A perennial plant re-grows year after year from the same root. Some perennial plants are very long-lived like an oak tree which others are short-lived like some of the newer coneflower cultivars.
Plants that are not winter-hardy are considered annuals in Minnesota, but are perennial in their native growing environment. An example is Tithonia rotundifolia which is grown as an annual flower here, but is a perennial shrub in its native Mexico and Central America.
Dividing perennials or “division” is a form of propagation: you are creating multiple plants from a single plant. Some plants like Heuchera, coral bells, are very easy to divide. The plant crowns are right at the surface of the soil and small plants, called offsets, develop from the larger main plant. Other plants like Hosta and ornamental grasses have dense roots that require a sharp knife, garden fork, or even an axe to cut apart.
Coral bells, also known as heuchera, are a popular flowering perennial grown for their attractive foliage. Their leaves come in a wide range of colors like lime green, burgundy, gold and silver. Some varieties also produce tiny bell-shaped flowers on tall stems.
As coral bells mature, they tend to grow into large clumps. This can lead to overcrowding, resulting in fewer blooms. The good news is that coral bells can be easily divided to prevent overcrowding and rejuvenate the plant
When to Split Coral Bells
The best time to split coral bells is in early spring, before new growth emerges. Spring gives the divided sections time to establish a strong root system before summer heat arrives.
Late summer or early fall is another option This allows the plants to establish themselves before winter dormancy, Just be sure to water regularly until the ground freezes,
Avoid splitting coral bells during summer or when they are blooming Heat and drought stress can cause transplant shock
How to Split Coral Bells
Dividing coral bells is a simple process. Follow these steps:
1. Prepare the Plant
Water the plant thoroughly a day before dividing. This makes it easier to remove from the ground.
Identify the sections you want to divide. Look for crowns that are growing up and out of the center of the plant. These offshoots will have their own root systems and are ideal for dividing.
2. Dig Up the Plant
Use a spade or garden fork to dig up around the plant, staying about 6 inches away from the base. Gradually lift the clump out of the ground.
You can also slice straight down through the center with a shovel to divide the plant in place. Then lift out each section.
3. Divide the Root Ball
Gently shake or rinse off excess soil from the roots. Then use a sharp, sterile knife or garden shears to split the root ball into smaller sections.
Each division should have 3-5 healthy leaves and plenty of healthy roots. Divisions that are smaller than 3 inches wide may not survive.
4. Replant Divided Sections
Plant the divisions in holes that are wider but no deeper than the root balls. Space them 12-18 inches apart in an area with rich, well-drained soil and partial sun.
Backfill the holes with native soil and pack firmly. Water thoroughly after planting.
Caring for Newly Divided Coral Bells
Dividing coral bells causes transplant shock. Provide a little extra care for a few weeks after splitting to help them recover quickly:
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Water regularly to keep soil evenly moist. Avoid overwatering.
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Apply a balanced fertilizer a few weeks after transplanting. This encourages new growth.
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Keep weeds pulled to prevent competition for water and nutrients.
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Watch for signs of stress like wilting, yellowing leaves or stunted growth. Problems usually clear up once the roots establish.
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Leave spent flower stems intact for winter interest. Cut them back in early spring.
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Mulch around the plants to conserve moisture and suppress weeds. Replenish as needed.
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Stake tall, floppy varieties that tend to fall over, especially after rains.
With a little TLC after transplanting, your divided coral bells will quickly regain their vigor. In no time, they will transform into beautiful, full-sized plants. Dividing is an easy, cost-effective way to expand your coral bell collection too!
Tips for Successfully Dividing Coral Bells
Follow these tips to ensure successful divisions that will thrive:
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Only divide large, mature clumps. Avoid smaller plants that may not survive.
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Disinfect tools with rubbing alcohol before each cut to prevent transmitting diseases.
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Water the plants well and allow the soil to dry slightly before dividing. This firms up the root ball.
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Make clean cuts through the roots and rhizomes using a sharp knife or garden shears. Ragged cuts can lead to rot and disease.
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Keep the divisions moist and transplant quickly after dividing. Allowing them to dry out reduces their chance of survival.
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Plant the divisions at the same depth they were originally growing at. Burying the crown can cause crown rot.
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Group varieties with similar light and soil preferences together for easier care.
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Label each new division so you don’t forget their variety names.
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Avoid overfertilizing, which can cause leggy, weak growth prone to flopping over.
By following proper technique, you can successfully divide overgrown coral bells into multiple new plants. In no time at all, you’ll have a beautiful collection of these easy-care perennials to enjoy.
Why divide? Plants like hosta become crowded, increasing potential hideaways for pests like slugs.
Division also promotes plant health and can rejuvenate a plant. A perennial should be divided when it dies out in the middle (the oldest part) of the plant, produces smaller flowers or leaves, and blooms less.
Dividing perennials is also a good idea if plants have become crowded as it increases air and light around plants which can increase blooming as well as reduce disease and insects pests. Plants like Nepeta (catmint), Agastache (hyssop), and Athyrium niponicum (Japanese painted fern) can be divided every year if necessary.
Some plants like Baptisia, false indigo, do not respond well to division because they have long, deep roots that are difficult to dig out without breaking them off. In fact, Baptisia shouldnt be divided or moved if possible!
Similarly, peonies have deep, fleshy roots that break easily. They not only can be tricky to dig up, but also must be replanted at the proper depth of 1 1/2 inches and it can take a few years before these divisions become established enough to bloom.
So how to remember all this? Our page How and when to divide perennials provides guidelines. It also includes a list of about 125 favorite herbaceous perennials that tells you when and how often to divide some of our favorite herbaceous perennials, and includes notes that provide helpful particulars on some of the more finicky plants we love.
Author: Julie Weisenhorn, Extension educator, horticulture
Two Ways to Divide and Propagate Coral Bells. AKA Heuchera micrantha.
FAQ
Do coral bells like full sun or shade?
Coral bells (Heuchera) are versatile plants that can thrive in both full sun and full shade, but partial shade is often considered ideal. While they can tolerate full sun, especially with proper watering and care, some varieties may scorch or fade in intense sunlight.
How to divide coral bells?
To divide coral bells, first dig up the plant and separate the clumps using clean and sharp tools. This task is essential for maintaining the plant’s vigor and propagating it. The best time to divide coral bells is either in spring or fall.
When should you split a Coral Bell plant?
Spring is the right time to split and transplant your coral bell or any other plant (source). Spring is the season when growth emerges in plants. Therefore, this is when your coral bell plant will have an easier time re-establishing its root system in a new pot.
Can coral bells go under Division?
Any garden can incorporate this plant. 6. Plant them in early fall and they will be fine. By next spring, they might even be ready to go under division. So your coral bells plant is about as big as a small pumpkin and you are ready to divide it. What do you do? Pull up the entire plant if it is fairly small and lightly pull at the root sections.
How to split a Coral Bell (Heuchera) plant?
You need to access your coral bell (Heuchera) plant’s root system for a safe splitting. Therefore, you must start by digging up the plant. The best way to dig up the plant is by thrusting a garden fork into the soil about 6 inches (15.24 cm) away from the base of the plant. You should then rock the fork back and forth to loosen the roots.
How to propagate coral bells?
Division is one of the best ways to propagate coral bells because it’s fast and easy, and it doesn’t require any special equipment. Plus, you can divide your plants every few years to keep them healthy and prevent them from getting too big for their space. These semi-evergreen perennials are known for their easy care and long life.
When is the best time to divide coral bells?
They can be divided both spring and fall, although fall is generally the best time. Division is one of the best ways to propagate coral bells because it’s fast and easy, and it doesn’t require any special equipment. Plus, you can divide your plants every few years to keep them healthy and prevent them from getting too big for their space.