13 Plants That Love to Be Divided

If you’re ready to do some garden rearranging, fall is the perfect time. Many plants respond well to division and transplanting at this time of year, and they love moderate and cooler conditions. Spring is ideal for dividing fall-boomers, while autumn is prime for spring and summer-flowering perennials.

Reasons to divide include rejuvenation, controlling size, and expanding the collection. Over time, the original plant becomes cramped and less vigorous. Dividing rejuvenates growth, prevents overcrowding, and promotes flowering. It restores health, allowing more space for roots to spread to absorb water and nutrients. It reduces competition for resources and stimulates new growth.

Division Basics

Dividing is a means of propagation and an easy way to increase numbers. Many perennial plants love division because it helps them thrive. It’s best to split up roots and leafy growth when they aren’t flowering. Choose a mild day, not intensely hot, for the least stress on the new and existing plants (bonus if it’s cloudy with rain in the forecast).

1. Water deeply the day before dividing for easy digging and turgid stems. With a spade or digging fork, dig a wide berth around the main crown or entire clump to lift it out of the soil.
2. Capture as many roots as possible. For some perennials, this may be only four to six inches away from the core material, depending on the size and depth of the root system.
3. Loosen roots and shake off excess soil. With a sharp blade or spade, separate the clump or core into sections. Each segment should have viable stems and roots attached. These become the new garden transplants.
4. Gauge the viability of the existing mother plant. Is the main central crown healthy and productive? If so, divide it into segments for replanting. If it is densely packed and lacking vigor and new growth, compost the old portion and rely on the newly divided plants for fast development.
5. Remove old, woody stems and debris. Clip off dead or diseased parts and dispose of them away from the bed. 

Replant the fresh additions in their garden spots, and water thoroughly to moisten the surrounding soil. Hold off fertilizing until spring for fall-planted additions. Add a generous layer of mulch, keeping it off of stems, for insulation and moisture retention.

Aster

	common name Aster
	botanical name Aster spp.
	sun requirements Full sun to partial shade
	height 1-8’
	hardiness zones 4-8

Asters are quintessential fall flowers with blue-purple or white daisy-ray flowers and contrasting yellow centers. They bloom in late summer in a blanket of color that lasts well into fall as many other plants begin to fade.

The pollinator favorites prefer moist, organically rich soils. To prevent foliar diseases, allow plenty of air circulation and ensure soils have good drainage.

Enjoy autumn’s floral show and plan to split aster in the spring. This plant loves and benefits from division every year or two to control the spread and maintain health. Take new growth from the outer edges of the crown and discard the older, central section if it’s no longer vital.

Coreopsis

	common name Coreopsis
	botanical name Coreopsis spp.
	sun requirements Full sun
	height 6”-4’
	hardiness zones 4-10

Coreopsis brings waves of sunny yellow in its long and prolific bloom season from early spring through late fall. The golden flowers are a rich nectar and pollen source for bees, butterflies, and other beneficial insects. 

Coreopsis is drought and heat-tolerant and grows across a range of conditions. It regularly self-seeds, providing forage for birds in the fall and winter and seedlings in the spring.

Break away new transplants every one or two years in spring or fall for the best vigor. Compost the mature core is growth is sparse. C. lanceolata and C. grandiflora live longer with crown division every two to three years.

Catmint

	common name Catmint
	botanical name Nepeta spp.
	sun requirements Full sun
	height 1-3’
	hardiness zones 3-8

Catmint is best known for its soft, mounding gray-green foliage and loads of purple trumpet flowers throughout the warm season. The aromatic leaves contain essential oils that repel certain garden pests while drawing feline visitors.

The profusion of lavender-blue blooms begins in early summer and lasts most of the season. The durable growers thrive with neglect and tolerate heat. Deadhead spent flower spikes or shear plants to encourage quicker reblooming after their initial flush.

Create new seedlings when the original is a few years old, as often as annually. In fall or spring, lift the clump and cut it into sections with roots and fresh growth intact. Replant the original.

Blanketflower

	common name Blanketflower
	botanical name Gaillardia spp.
	sun requirements Full sun
	height 1-2’
	hardiness zones 3-9

Blanketflower offers whirling flowers in yellow, orange, red, and bi-color. Brown button centers dot the daisy petals. Highly adaptable, Gaillardia thrives in various sites, from beach dunes to open meadows.

The North American native wildflower is drought and heat-tolerant and grows in poor, sandy soils. It needs well-drained situations and withers in waterlogged soils.

Removing old stems promotes flowering and tidies the plant, but it is not essential. When they show less robust growth (every two to five years), dig up and pull the spreading roots apart by hand. Tease out fresh transplants.

Chrysanthemum

	common name Chrysanthemum
	botanical name Chrysanthemum spp.
	sun requirements Full sun to partial shade
	height 2-4’
	hardiness zones 3-9

Perennial garden mums are cold-hardy and grow vigorously with a clumping habit. They’re the gems of the autumnal display with rich shades of gold, plum, and scarlet among dark, lobed leaves.

Hardy mums have shallow root systems that are easily dug and transplanted. The best time to divide the fall-bloomers is in the spring as new growth emerges and when shoots reach one to three inches long. Chrysanthemums love division every two to three years when established plants show crowded central crowns with less vigor and flowering.

Coral Bells

	common name Coral Bells
	botanical name Heuchera sanguinea
	sun requirements Full sun to partial shade
	height 1-2’
	hardiness zones 3-8

Coral bells are dynamic in the shady border with stunning foliage and a low, mounding habit. The North American natives have attractive green leaves and sweet bloom sprays in pinky-red, with hybrids in lime, purple, bronze, red, and silver foliage.

Heuchera needs rich, organic, well-draining soils. Once established, it tolerates moderate drought.

To rejuvenate the crop, cut the crown every two to three years or gently separate roots and stems from the perimeter for new seedlings. Toss the parent plant if its core struggles to present fresh stems and foliage.

Iris

	common name Iris
	botanical name Iris spp.
	sun requirements Full sun
	height 1-3’
	hardiness zones 5-9

The Iris genus houses hundreds of species and thousands of varieties in a rainbow assortment of flower forms. Popular garden selections include bearded, crested, Siberian, Japanese, and sweet. 

Irises grow best in organically rich soils with consistent moisture, though many tolerate dry conditions. Clumps divide easily to distribute the collection. Split the colony from one month after its summer flowering until early fall.

Aim to retain a few inches of the rhizome with at least one fanned blade attached. Trim the leaf in half and replant the rhizome with the top just above the soil level. Robust spreaders like bearded iris benefit from reducing crowding and control spread every one to three years, while slower selections like Siberian only need it every six to ten.

Bee Balm

	common name Bee Balm
	botanical name Monarda didyma
	sun requirements Full sun
	height 2-4’
	hardiness zones 4-9

Bee balm is native to the eastern U.S. and features flared scarlet blooms along its tall stems. Blue-green foliage is minty, spanning the ornamental and edible garden.

The bloom season is long, lasting from early summer until freezing temperatures. Monarda grows best with good air circulation, organic soils, and consistent moisture. 

It spreads by both seed and rhizomes. Divide plants and weed out volunteers as clumps expand, usually every one to three years. Select tender new growth and discard thinning crowns.

Astilbe

	common name Astilbe
	botanical name Astilbe spp.
	sun requirements Partial to full shade
	height 3’
	hardiness zones 4-9

Astilbe is a woodland selection with feathery plumes above ferny leaves. The dense, pyramidal bloom spikes hold hundreds of florets that open in succession. In shades of pink, peach red, purple, champagne, or white, the blooms set in spring and open through early summer.

Showy seed heads follow the flowers for lasting interest. Glossy green leaves have tinges of red and copper.

Astilbe appreciates consistently moist and rich soils. Based on its flowering responses, we know that this plant loves and appreciates division every two to three years for more blooms.

Allium

	common name Allium
	botanical name Allium spp.
	sun requirements Full sun
	height 1-3’
	hardiness zones 4-9

Alliums feature an array of species that offer ornamental value. From giant alliums and their globes of purple blossoms to compact perennials, they’re at home in the border. 

Related to onions and chives, ornamental varieties feature bladed leaves and spheres of star-shaped florets but grow for their form rather than flavor. Pollinators flock to the showy globes.

You may notice groups becoming overcrowded with less flowering. After foliage fades, dig, split, and replant the bulbs in the fall.

Yarrow

	common name Yarrow
	botanical name Achillea millefolium
	sun requirements Full sun
	height 1-3’
	hardiness zones 3-9

Yarrow boasts feathery foliage, large flower clusters, and a no-fuss culture. Its broad blooms in bright yellow (and numerous colorful cultivars) are a valuable food source for pollinators and other beneficials.

The drought-tolerant North American natives flourish in the summer heat in all kinds of soils as long as they’re well draining.

You’ll know it’s time to refresh yarrow when its woody center shows signs of decline. Every two to three years, cut or hand-separate fresh sections of new growth for replanting. Compost the aged core and its thick-wooded stems.

Rudbeckia

	common name Rudbeckia
	botanical name Rudbeckia fulgida
	sun requirements Full sun to partial shade
	height 2-3’
	hardiness zones 3-9

Black-eyed Susan is an anchor of the perennial bed, with carefree growth and cheerful, golden ray flowers with chocolate button centers. The North American wildflower blooms all summer through frost.

A hearty bloomer, Rudbeckia withstands hot, humid, and dry conditions. It adapts to various soils and light exposure.

Black-eyed Susan self-seeds and also spreads slowly through underground rhizomes. Divide clumps every three to five years to keep them vigorous and full of sunshiney floral love.

Phlox

	common name Phlox
	botanical name Phlox paniculata
	sun requirements Full sun to partial shade
	height 2-4’
	hardiness zones 4-8

Tall garden phlox is showy and fragrant with domes of pink bloom clusters. The native perennial attracts butterflies and hummingbirds with its flowers from summer until frost. 

Cultivars boast deep pink, red, magenta, purple-blue, and bicolor blooms. They often have greater disease resistance and improved forms.