Keeping perennials thriving isn’t just about watering and fertilizing—some plants need to be divided to stay healthy and bloom their best. Splitting them every few years prevents overcrowding, keeps them vigorous, and even gives you more plants for free! But not all perennials like to be disturbed. In fact, some do better when left alone. In this guide, you’ll learn which 20 perennials thrive when divided and the 5 that should stay right where they are.
1. Hostas
These leafy beauties might take over your garden if left unchecked. Hostas thrive when divided every three to four years. Their lush foliage, ranging from deep green to variegated patterns, adds texture to any garden.
By dividing them, you not only control their spread but also encourage more vigorous growth and healthier plants.
Remember to divide them in early spring or fall, giving each new clump plenty of room to stretch its roots. You’ll be rewarded with a garden full of rich, vibrant leaves and happy, healthy hostas.
2. Daylilies
Daylilies are the divas of the garden, demanding attention with their vibrant blooms. These perennials benefit from division every three to five years.
By splitting them, you prevent overcrowding, which can lead to fewer flowers. The best time to divide is after they’ve finished blooming.
Each division will reward you with more flowers in the following seasons. Plus, sharing divisions with friends can spread the joy of these colorful blossoms. Your garden will thank you with an abundance of cheerful flowers.
3. Irises
Irises are the elegant dancers of the plant world, with their graceful, flowing petals. Dividing them every three to five years ensures they don’t wear themselves out.
Overcrowded irises might stop blooming, so dividing helps rejuvenate them. It’s best done in late summer when they’ve finished their show.
Each divided rhizome will eventually explode with color, giving your garden a stunning display. These beauties will continue to captivate with their intricate blooms and striking presence.
4. Peonies
Peonies are the crowned jewels of any garden, demanding admiration with their lush, full blooms. Dividing them every five to ten years helps maintain their vigor.
Doing this in the fall allows them to settle before winter. When divided properly, each peony clump will grow robust and produce abundant blooms.
Their intoxicating fragrance and stunning style will continue to enchant, making your garden a romantic escape. Peonies promise a timeless elegance that few can resist.
5. Sedum
Sedum, or stonecrop, is a hardy succulent that loves to spread its wings. Dividing every three to four years keeps them from becoming overcrowded.
These plants are drought-tolerant and thrive in well-drained soil. By dividing sedum, you encourage new growth and prevent older plants from dying out.
A garden adorned with sedum is both colorful and resilient, able to withstand the toughest conditions.
6. Bee Balm
Bee balm is a pollinator’s paradise, drawing bees and butterflies with its vibrant blooms. To keep it thriving, divide every two to three years.
This prevents it from becoming too crowded and susceptible to mildew. Dividing bee balm also promotes healthier, more prolific blooms. It’s best done in early spring.
With their bright colors and delightful scent, bee balm will make your garden a lively haven.
7. Yarrow
Yarrow is a steadfast garden friend, known for its feathery foliage and bold blooms. Dividing it every three to four years keeps it from becoming leggy.
Division encourages compact growth and more flowers. Yarrows are tough, drought-resistant, and ideal for sunny spots. By dividing and replanting, you can fill your garden with these low-maintenance beauties. They add a splash of color and are great for cutting gardens, continuing to brighten your space year after year.
8. Shasta Daisies
There’s something about Shasta daisies that screams summer joy. Their cheerful blooms benefit from division every two to three years.
Overcrowding can lead to fewer flowers and weaker plants. Dividing helps rejuvenate them, ensuring robust growth. Do this in early spring or fall, and you’ll have a garden full of these cheerful sun-catchers.
Sharing divisions with friends can spread the joy and keep your garden glowing with happiness.
9. Phlox
Phlox adds a splash of color with its dense clusters of flowers that are hard to resist. Dividing every three to four years keeps them from getting sparse.
This helps maintain their bushy form and encourages more blooms. Best done in spring or fall, division gives each new plant room to thrive.
With phlox in your garden, you’ll have a burst of color and an inviting space for butterflies. It’s a classic choice that never goes out of style.
10. Lamb’s Ear
Lamb’s Ear, with its soft, silvery leaves, adds a unique texture to gardens. Dividing every three to four years prevents the center from dying out.
This keeps the plant healthy and attractive. Lamb’s Ear is perfect for edging pathways and thrives in dry, sunny areas.
By dividing, you promote new growth and can spread its soft, tactile beauty throughout your garden.
11. Astilbe
Astilbe is the garden’s feather duster, with its delicate, plumed flowers. These perennials need dividing every three to four years.
Doing so prevents them from becoming overcrowded and revitalizes their blooms. Astilbe thrives in shaded, moist areas and can add elegance to any garden.
Once you divide them, you ensure their feathery plumes continue to dance gracefully in the breeze. Their charming presence makes for a delightful addition to any landscape.
12. Japanese Anemone
Japanese anemones bring a touch of elegance with their dainty blooms. Dividing every three to four years keeps them from taking over.
These plants are best divided in spring or fall and will reward you with a more controlled appearance. Each division can grace your garden, adding a splash of color and grace.
With their delicate flowers, Japanese anemones turn any garden into a serene escape.
13. Rudbeckia
Rudbeckia, also known as black-eyed Susans, brighten gardens with their sunny faces. Dividing every three to four years keeps them lively and full of blooms.
Remember that these plants can become crowded, leading to fewer flowers. By employing this technique, you stimulate growth and spread their cheerful presence.
Each section can be planted to fill the garden with these golden beauties, ensuring a sun-kissed landscape.
14. Coreopsis
Coreopsis is the garden’s ray of sunshine, known for its cheerful yellow blooms. Dividing every two to three years prevents them from becoming too leggy.
This encourages bushier growth and more abundant flowers. Dividing coreopsis is best done in spring.
With their sunny disposition, coreopsis ensures your outdoor space remains radiant and inviting.
15. Echinacea
Echinacea, or coneflowers, stand out with their bold, spiky blooms. Dividing them every three to four years keeps them in peak condition.
Over time, they can become crowded, reducing flower production. This method encourages fresh growth and a continuous display of flowers.
Echinacea is a favorite among pollinators, and each division will ensure your garden attracts bees and butterflies.
16. Asters
Asters are a must-have for any fall garden, bringing a burst of colors when most plants are winding down. Dividing asters every 2-3 years encourages robust growth and more blooms. Choose early spring to perform the division for the best results.
Carefully lift the plants and split them into smaller groups. Plant them in sunny spots with fertile soil. This will ensure they continue to dazzle with their cheerful blossoms come autumn.
17. Catmint
Catmint is the garden’s aromatic delight, offering lovely blue blooms and fragrant leaves. Dividing every three to four years prevents it from becoming unruly.
This encourages tidy growth and more prolific flowers. Catmint thrives in sunny spots and is a favorite for attracting pollinators. Your space will be a fragrant, buzzing paradise.
18. Bergenia
Bergenia, known for its bold leaves and spring blooms, benefits from division every three to four years.
This prevents overcrowding and encourages robust growth. Bergenia thrives in both sun and partial shade, making it versatile for various garden spots.
You can plant each section to maintain its vibrant presence. With bergenia, your garden will have a touch of bold foliage and colorful blossoms.
19. Fern
Ferns bring a woodland charm with their graceful fronds. Dividing every three to five years keeps them lush and prevents overcrowding.
These stunning plants thrive in shaded, moist conditions and are perfect for adding texture to any garden. Your garden will have a lush, green backdrop that’s both serene and stylish.
20. Dianthus
Dianthus, with its spicy fragrance and colorful blooms, is a garden favorite. Dividing every three to four years keeps them from becoming overgrown.
This encourages compact growth and abundant flowers. Dianthus thrives in well-drained soil and sunny spots, making them versatile for various garden styles. Each divided section can add a pop of color and sweet scent, ensuring your garden remains a perennial favorite.
21. Don’t Divide Bleeding Heart
This delicate beauty thrives in shaded gardens, producing heart-shaped blooms in spring. Bleeding hearts have brittle, fleshy roots that don’t tolerate division well.
If disrupted, they can struggle to recover, leading to fewer flowers. Instead of dividing, allow them to self-seed naturally or propagate through cuttings.
22. Baptisia Prefers To Be Left Alone
Baptisia develops a deep, extensive root system that makes division nearly impossible. Once established, this plant is best left alone, as disturbing the roots can stunt growth or even kill the plant.
If you need more, collect seeds and start new plants rather than trying to divide mature clumps.
23. Avoid Dividing Monkshood
Monkshood is a striking perennial with tall spikes of deep purple flowers, but its roots are extremely sensitive.
Attempting to divide it can damage the plant and disrupt its growth. Instead, let it spread naturally or propagate by taking stem cuttings in early summer.
24. Lupines Suffer If Divided
Lupines have a taproot system that makes them difficult to divide successfully. Their long, deep roots don’t respond well to being cut or moved, often leading to transplant shock.
To expand your lupine collection, collect seeds or let them reseed naturally in your garden.
25. Leave Lavender Alone
Lavender prefers dry, well-drained soil and doesn’t like having its roots disturbed. Dividing it can lead to root rot and a decline in vigor.
Instead, propagate lavender through cuttings to create new plants while keeping the original healthy and thriving.
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