Do you often wonder whether you should be splitting and transplanting your perennials in the fall or the spring? I’ve created a guide that includes some of the more popular plants below, with the best times for dividing perennials, and how to do so.

Timing is Key
Timing and technique are everything when it comes time to dividing perennials. And while many perennials can be divided in either early spring or early fall, some plants can be extremely sensitive to when they should be split. I’ve listed the most optimal times to divide specific perennials below.

The Reasons to Divide Your Perennials…
- Keeps the plant healthy. It gives the plant more space for roots to grow and absorb nutrients and water.
- Increases the number of blooms.
- Manages the size of the plant and keeps it from overcrowding other plants.
- Dividing every 3-4 years will keep the plant from dying out in the middle, leaving a bare hole.
- Creates more plants for future plantings in your garden


PERENNIALS TO DIVIDE BY HAND
Plant name Botanical name | Season | Instruction |
---|---|---|
Bleeding hearts Dicentra | Spring | Divide after the plant flowers |
Dianthus Dianthus | Spring, Summer | Mat-forming types root as they grow; cut a rooted piece from the edge and replant |
Hellebore Helleborus | Spring | Does not need to be divided often, but when you do, divide when plants are in bloom, or right after they stop flowering |
Lady’s mantle Alchemilla mollis | Spring, Fall | Easier to divide in early spring as leaves begin to emerge; does not need to be divided often |
Lamb’s ear Stachys byzantina | Spring, Summer, Fall | Roots are along the stem; cut a piece off the edge and replant; cut leaves back by half |
Primroses Primula | Spring | Transplant after plant has finished blooming |
Salvia Salvia | Spring, Fall | Divide every 5 or 6 years or when plant dies out in the center; divide in the spring in cold and winter climates. |
Yarrow Achillea | Spring, Summer | Easy to divide; most types spread quickly so divide every 2 to 3 years |

PERENNIALS TO DIVIDE WITH A SPADE OR PITCHFORK
Plant name Botanical name | Season | Instruction |
---|---|---|
Anemone Anemone × hybrida | Spring | Division is rarely needed, maybe once every eight to 10 years. Transplanting should be done in the spring |
Asters Aster | Spring | Dividing aster plants in spring will allow the new plants time to establish before the end of summer |
Bee balm Monarda didyma | Spring, Fall | Divide every 2-3 years in the early spring |
Black-eyed Susan Rudbeckia | Spring, Fall | Divide every 3 to 4 years; for best appearance next season, don’t make divisions too small |
Catmint Nepeta × faassenii | Spring, Fall | Divide every 3-4 years in either spring or early fall |
Coneflower Echinacea purpurea hybrids | Spring, Summer, Fall | Divide every 4 to 5 years for healthier plants; reseeds and seedlings are easy to transplant |
Daylily Hemerocallis hybrids | Spring, Summer, Fall | Divide every 5 to 7 years; rebloomers are best lifted in spring before they flower |
Garden mum Chrysanthemum hybrids | Spring | Easy to divide; divide every 2 to 3 years to keep plants blooming and vigorous; discard dead central portion |
Garden phlox Phlox paniculata | Spring, Summer, Fall | Divide every 3 years or when flowering diminishes; discard the woody center and plant the edge pieces |
Goldenrod Solidago | Spring, Fall | Divide every 3 to 5 years to keep plants vigorous |
Hostas Hosta hybrids | Spring, Summer, Fall | Easy to divide in early spring when foliage is emerging; dividing large clumps later won’t harm plants but leaves them lopsided for the summer |
Sedum Autumn Joy Sedum | Spring, Summer, Fall | Easiest to divide in spring when foliage is still small; dividing clumps later won’t harm plant but may reduce bloom for the year |
Shasta daisy Leucanthemum x superbum | Spring, Summer, Fall | Easiest to divide in spring when foliage is still small; dividing clumps later won’t harm plant but will reduce bloom and leave plants lopsided for the year |
Yarrow Achillea | Spring, Summer | Easy to divide; most types spread quickly so divide every 2 to 3 years |

CUT UP RHIZOMES AND TUBERS WITH A KNIFE
Plant name Botanical name | Season | Instruction |
---|---|---|
Calla lily Zantedeschia aethiopica | Spring | Most gardeners prefer to divide calla lilies in spring, especially in warm climates where you can leave the rhizome in the ground year round. |
Dahlias Dahlia | Spring | In warmer climates where the tubers remain in the ground, you can dig up, divide, and replant the tubers in early spring. If you are overwintering tubers, you can divide in the fall. |
Irises Iris | Fall | Using a knife or hands, break the rhizomes apart in groups of 1-3. Cut the foliage down by half with pruners. |
Lily-of-the-valley Convallaria majalis | Spring, Summer, Fall | Rhizomes pull apart easily; make sure each new division has a leaf and a cluster of roots |
I hope this gives you a better idea as to when the best time for dividing your perennials is. It’s so important to divide your plants for them to remain healthy and increased the amount of blooms. It also helps to keep your garden from overcrowding.
And my favorite reason for dividing perennials? They are the gift that keeps on giving year after year. I rarely have to go to the nursery and buy new perennials because I am constantly transplanting new plants throughout the garden.
Learn more about preparing your garden for winter.
Resources: Calla Lily Division and How to Divide Irises

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Kim – I’ve always buried my head in the sand about dividing plants. Somehow it felt very complicated and scary. Now that we’ve planted our new garden, I’m determined to become a better gardener. You’re gardens are spectacular so I’m going to take your advice. Thanks for the info! xo
I used to feel the same way Juliet. But I have to say, it is so much easier than it looks. You can do it!