Dividing Perennials: The Key to a Lush and Expanding Garden

Perennial plants benefit your garden by providing beautiful flowers that return year after year. They adorn our gardens with various vivid colors and unique leaf shapes. However, creating and maintaining a visually beautiful perennial garden takes time and effort. You can easily increase the impact by dividing your favorite plants every two years or so. The amazing results you will obtain from dividing perennials are well worth the time and energy invested.

These perennials may start to bloom less frequently after a few years in the garden and develop a bald spot in the middle of their crown. These are all signs indicating that it's time to divide your plants. However, reduced plant performance is not the only reason for the division of perennials.

Dividing perennials will ensure strong, healthy plants that will continue to thrive year after year. It also gives you the chance to grow more plants. For the best results, gardeners should know when and how to divide them.

This is a complete guide on dividing perennials, including why, when, and how to do it properly for a thriving perennial garden.

Why You Need to Divide Perennials

Control Size: Plants grow at different speeds. Therefore, division can keep quickly spreading plants under control.

Promote New Growth: When perennials become overgrown and overcrowded, they often do not bloom as much. Dividing will help rejuvenate the flower show. Plants in overcrowded conditions compete for nutrients and water. Dividing the perennial plants into smaller portions lowers competition, encourages new growth, and promotes more blooming.

Multiply Plants: Division is a simple and cost-effective method to increase the number of plants in your garden.

When to Divide Perennials

Plants can be successfully divided nearly any time if properly watered afterward. However, division is most effective when the plants are not actively growing. Divide the plant while it is not flowering so that it can focus all its energy on regenerating roots and leaf tissue.

Divide Fall Blooming Perennials in Spring

Divide fall-blooming plants in the spring when new growth emerges, and it's easier to see what you're doing. During this time of year, the weather is cool, and the soil has enough moisture to support root growth and development.

Smaller leaves and shoots will not be as damaged as fully grown leaves and stems. The stored energy in the plant's root system will help the plant recover after being cut apart and replanted. Moreover, rain showers usually come in early spring, benefiting your perennial garden. Perennials divided in the spring have one entire growth season to recover before winter.

Divide Summer Blooming Perennials in Fall

Divide spring—and summer-blooming plants in the fall because gardening in the fall requires less work than in spring. Also, it is easy to find plants that need division. Some sources also recommend dividing spring-blooming plants in April or May, just after the plant finishes flowering. Regardless of the time chosen, divide the plant when it is not in bloom so that the plant can direct all its energy toward root and leaf growth.

Perennial plants with fleshy roots, such as peonies, Siberian iris, and Oriental poppy, are best divided in the fall. When dividing perennials in the fall, time it for 4 to 6 weeks before the ground freezes to allow the roots to establish. This is important in colder northern areas.

Tips and Guidelines on Dividing Perennials

Below are some helpful expert tips for dividing plants successfully.

• Divide plants on a cloudy day, as dividing on a hot sunny day can dry out the plants.
• If the area is dry, water it the day before. Divide plants when there are a few rainy days in the forecast to ensure enough moisture for the new transplants.
• Divide perennials in cool weather like spring and early fall to allow roots to grow.
• Before replanting, replenish the soil by mixing compost and organic matter.
• After dividing, replant parts 20-25% of the original cluster. Smaller sections develop faster and produce more robust, long-lasting flowers.
• If your plant shows signs of poor health, pest infestation, and diseases, be careful and replant only the healthiest parts.
• Some perennials thrive if kept intact and not divided, so leave them. These include baptisia, lavender, bleeding heart, Christmas rose, and gas plant.
• Perennials that should be divided every 3 to 4 years include hosta, peony, phlox, bee balm, daylily, purple coneflower, Siberian iris, and black-eyed Susan.
• Perennial plants that should be divided every 2 to 3 years include aster, coreopsis, blanket flower, yarrow, clustered bellflowers, and lamb's ears.

How to Divide Perennials

Here are the steps to divide your perennial plants:

1. Dig up the parent plant using a shovel, spade, or garden fork.
2. Force your fork or shovel under the root ball and move it up and down to loosen it.
3. Carefully lift the plant from the ground and remove loose soil around its roots until they are visible.
4. Divide the parent plant into smaller parts by any of the following methods:

• Small, fibrous-rooted perennials such as Hosta, Epimedium, and Heuchera can be pulled apart gently with your hands.
• Cut them with a knife or axe. This is best for plants with woody crowns, such as Helleborus.
• Put two garden forks in the clump back-to-back, use them as levers, and pull them to split the plant into two sections. This method is used to divide large, fibrous-rooted perennials like daylilies.

5. Each plant division should have a minimum of three to five strong shoots and abundant roots.
6. Keep the divisions protected and moist until they're replanted.
7. Replant them as soon as possible.

Aftercare

Plant divisions immediately and water them thoroughly. They can be replanted in the same location by mixing some garden compost and other soil amendments or relocating to a new garden area. Alternatively, pot up divisions individually to increase growth and keep pots in a frost-free location.

The Bottom Line

Dividing your plants regularly will help you keep your beautiful plants healthy and save money. When perennials are divided, their roots have more space to grow and absorb nutrients and water. How lovely it is that you can revitalize even the oldest plants of your garden by dividing them. Dividing a single perennial into many plants also improves its health and growth.

So, grab your tools and divide your plants to create a healthy and beautiful perennial garden.