Divide your perennials to keep plants vigorous, improve the health of their foliage and to increase the number of blooms. Or simply divide them for the sake of having multiple of your favorite plants! Because every perennial has a preferred way to be divided, use this handy chart to help you know what time of year to divide, how to divide it and a handful of other helpful tips to ensure your success.
Keep in mind that each perennial’s root type determines how it likes to be cut and divided. For more information head to over to Three Ways to Divide Perennials to help you know.
| Plant name Botanical name | What season to divide | Root type | Special tips |
|---|---|---|---|
| Astilbe Astilbe spp. |
Spring, Fall | Clump | Divide in early spring or after it stops blooming in late summer to early fall; will bloom better with division every 2 to 3 years |
| Bachelor’s button Centaurea montana | Spring, Fall | Clump | Easy to divide; needs to be divided every 1 to 2 years to keep plants vigorous |
| Bearded iris Iris hybrids |
Summer | Rhizome | Divide in summer when flowering is over, at least 6 weeks before frost so plants have time to get established |
| Bee balm Monarda spp. |
Spring, Summer | Rhizome | Spreads quickly; easy to divide; for ease of handling, divide in spring as foliage is emerging |
| Black-eyed Susan Rudbeckia spp. |
Spring, Fall | Clump | Easy to divide; divide every 3 to 4 years; for best appearance next season, don’t make divisions too small |
| Blanket flower Gaillardia x grandiflora |
Spring, Fall | Clump | Easy to divide; roots usually pull apart easily by hand; divide every 3 to 4 years |
| Bleeding heart, old-fashioned Lamprocapnos spectabilis |
Spring, Summer, Fall | Clump | Divide as foliage goes dormant in the heat or mark plant location; roots are brittle, handle carefully |
| Brunnera Brunnera macrophylla | Spring, Summer | Clump | Divide in late spring to early summer, after blooming; will reseed but divide to keep specific cultivars true |
| Bugleweed Ajuga reptans |
Spring, Summer, Fall | Clump, spreads by stolons | Plants root as they spread; no need to dig whole plant; cut off rooted outer pieces and replant |
| Butterfly weed Asclepias tuberosa |
Spring | Clump | Difficult to divide because of taproot; for best results, purchase new plants |
| Catmint Nepeta x faassenii |
Spring, Summer | Clump | Doesn’t need division often; cut back whole plant by half so roots have less foliage to support |
| Columbine Aquilegia hybrids |
Summer, Fall | Woody crown | Divide every few years to keep this short-lived perennial around; reseeds but seedlings may not look like parent plants |
| Coneflower Echinacea purpurea hybrids |
Spring, Summer, Fall | Clump | Easy to divide; divide every 4 to 5 years for healthier plants; reseeds and seedlings are easy to transplant |
| Coral bells Heuchera hybrids |
Spring, Summer, Fall | Woody crown | Don’t worry about getting roots with each piece, they’ll sprout from the stem; cut individual leaves back by half to conserve moisture |
| Coreopsis Coreopsis grandiflora |
Spring, Summer | Clump | Division every 3 to 4 years helps this short-lived perennial stay around longer; cut plant back by half |
| Daylily Hemerocallis hybrids |
Spring, Summer, Fall | Clump | Divide every 5 to 7 years; rebloomers are best lifted in spring before they flower |
| Delphinium Delphinium spp. |
Spring | Clump | Blooms best if divided down into small sections; division every 2 to 3 years will prolong plants’ life |
| Dianthus Dianthus spp. |
Spring, Summer | Clump | Mat-forming types root as they grow; cut a rooted piece from the edge and replant |
| European wild ginger Asarum europaeum |
Spring, Summer, Fall | Rhizome | Easy to dig and split; likes moist to wet soils, so keep new plants well watered |
| Fall anemone Anemone spp. |
Spring | Woody crown, spreads by runners | Doesn’t like to have main clump disturbed; sends out underground runners so dig small new plants around the edges to transplant |
| False indigo Baptisia australis |
Spring | Clump | Difficult to divide because of taproot; for best results, purchase new plants; slow to recover from being moved |
| Feather reed grass Calamagrostis acutiflora |
Spring | Clump | Divide in spring; lift clump and cut into sections; you may need a saw or hatchet to divide roots |
| Garden mum Chrysanthemum hybrids |
Spring | Woody crown | 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 | Clump | Divide every 3 years or when flowering diminishes; discard the woody center and plant the edge pieces |
| Geranium, hardy Geranium spp. |
Spring, Summer, Fall | Woody crown | A ring of foliage around a dead center tells you it’s time to divide; usually every 3 to 4 years is sufficient |
| Goat’s beard Aruncus dioicus |
Spring | Clump | Rarely needs to be divided; tough roots make dividing difficult; leave plenty of room around new transplants because the plant gets large |
| Goldenrod Solidago spp. |
Spring, Fall | Clump | Divide every 3 to 5 years to keep plants vigorous |
| Hellebore Helleborus spp. |
Spring | Clump | Rarely needs to be divided; if you do divide it, do it in early spring while plants are in bloom or right after they stop flowering |
| Hosta Hosta hybrids |
Spring, Summer, Fall | Clump | 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 |
| Japanese painted fern Athyrium niponicum pictum |
Spring, Fall | Clump | Rarely needs to be divided, so divide only for new plants, every 7 to 8 years |
| Joe-Pye weed Eupatorium purpureum |
Spring, Fall | Woody crown | Divide in early spring for easy handling; for fall division, cut back flowers; may need a saw or hatchet to cut apart woody crown |
| Lady’s mantle Alchemilla mollis |
Spring, Fall | Clump | Divide in spring or fall; easiest in early spring as leaves begin to emerge; doesn’t need frequent division |
| Lamb’s ear Stachys byzantina |
Spring, Summer, Fall | Clump | This hardy plant roots along the stem; cut a piece off the edge and replant; cut leaves back by half; don’t overwater |
| Lily-of-the-valley Convallaria majalis |
Spring, Summer, Fall | Rhizome | Rhizomes pull apart easily; make sure each new division has a leaf and a cluster of roots |
| Lungwort Pulmonaria hybrids |
Summer, Fall | Clump | Big leaves wilt easily; cut each leaf back by half and keep summer transplants well watered |
| Maiden grass Miscanthus spp. |
Spring | Clump | Divide in early spring; use a hatchet or saw to cut clump apart; can dig whole clump to divide or chop out segments |
| Oriental poppy Papaver orientale |
Summer | Woody crown | Divide in midsummer; foliage goes dormant quickly after flowering so mark the plant’s location; keep new transplants watered |
| Peony Paeonia spp. |
Summer, Fall | Clump | New plants will take a few years to flower; set new plants at same depth as they were previously or they won’t bloom; keep watered; does not need to be divided often |
| Russian sage Perovskia atriplicifolia |
Spring | Woody crown | Very difficult to divide because of taproot; for best results, purchase new plants |
| Salvia Salvia spp. |
Spring, Fall | Clump | Divide every 5 or 6 years or when plant dies out in the center |
| Sedum (tall) Sedum spp. |
Spring, Summer, Fall | Clump | 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 | Clump | 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 |
| Speedwell Veronica hybrids |
Spring, Summer | Clump | Easy to slice into pieces; make sure to get plenty of roots with each new section |
| Turtlehead Chelone lyonii |
Spring, Fall | Clump | Divide every 4 years or as needed; if you divide in fall, wait until the plant is done flowering |
| Yarrow Achillea spp. |
Spring, Summer | Clump | Easy to divide; most types spread quickly so divide every 2 to 3 years |
