Dividing Native Perennials

Native perennials may benefit from periodic division to improve their vigor and appearance. Indications that a plant requires division are dead sections at the center of the clump, reduced size or abundance of flowers, or sparse foliage. Division can rejuvenate the plant and stimulate new growth. Perennials can also be divided for propagation purposes.

This table of common perennials indicates the root type of each plant, the best season for division (if appropriate), and specific advice on frequency and manner of division.

Perennial	Root Type	Season To Divide	Notes
Allegheny Spurge Pachysandra procumbens	Rhizomes	Late Summer	Spreads slowly, unlike invasive non-native P. terminalis Divide established clumps in August or September
Anise Hyssop Agastache foeniculum	Clumping	Spring	Divide every 3-4 years Make sure each section contains roots & top growth
Beardtongue Penstemon digitalis	Clumping	Spring	Divide with spade or garden fork every 1-3 years
Blazing Star Liatris spicata	Corm	Spring	Divide every 4-5 years to keep plants vigorous
Blue Vervain Verbena hastata	Clumping	Early Fall	Divide with a spade after flowering
Blue Wild Indigo Baptisia australis	Taproot	Not suitable for division	Difficult to divide because of taproot Resents disturbance; slow to recover from being moved
Blue-stemmed Goldenrod Solidago caesia	Rhizomes	Spring	Spreads, but not aggressively Divide rhizomes
Butterfly-weed Asclepias tuberosa	Taproot	Not suitable for division	Difficult to divide because of taproot Best to purchase additional plants
Cardinal Flower Lobelia cardinalis	Clumping	Spring	Short-lived; allow to self-seed Remove young offsets from basal rosette of mature plant
Coastal Plain Joe-pye-weed Eutrochium dubium	Woody crown	Spring or Early Fall	Does not require frequent division for plant health Divide in early spring for easiest handling May need a saw or hatchet to cut apart woody crown
Culver’s Root Veronicastrum virginicum	Clumping	Spring or Late Fall	Divide every 4-5 years Be sure each rootstock segment has a bud
Dwarf Crested Iris Iris cristata	Rhizomes	Early Fall	Divide every 3-4 years when leaves begin to turn yellow
Eastern Blue-star Amsonia tabernaemontana	Clumping	Not suitable for division	Seldom needs division; divisions are slow to establish
Eastern Prickly-pear Opuntia humifusa	Clumping	Growing Season	Break off pads at joint; let them dry, and stick in prepared soil New roots form very quickly Use gloves to protect hands from barbed hairs (glochids)
Eastern Red Columbine Aquilegia canadensis	Woody crown	Not suitable for division	Dislikes disturbance; short-lived but reseeds easily Moves about garden, favoring pathways and sidewalk cracks
Foamflower Tiarella cordifolia	Clumping	Spring or Early Fall	Divide by hand
Garden Phlox Phlox paniculata	Clumping	Spring or Late Summer	Divide every 2-4 years when flowering diminishes Discard woody center and replant edge pieces Regular division minimizes susceptibility to powdery mildew
Golden Ragwort Packera aurea	Stolons	Early Spring	Self-seeds & spreads aggressively by stolons from central rosettes Divide in early March before flowering
Great Blue Lobelia Lobelia siphilitica	Clumping	Spring	Short-lived; self-sows readily Remove young offsets from basal rosette of mature plant
Great White Trillium Trillium grandiflorum	Rhizomes	Not suitable for division	Best left to experts; plants take 4-5 years to flower
Green-and-Gold Chrysogonum virginianaum	Rhizomes	Late Spring	Spreads slowly by rhizomes
Hairy Alumroot Heuchera villosa	Woody crown	Spring or Early Fall	May not get roots with each piece; they will sprout from stem Cut leaves back by half to conserve moisture
Jacob’s Ladder Polemonium reptans	Clumping	Early Spring	Spreads slowly by self-seeding Divide clumps in early spring or late summer
Large-flowered Bellwort Uvularia grandiflora	Clumping	Spring or Early Fall	Divide mature clumps
Mayapple Podophyllum peltatum	Rhizomes	Fall	Colonizes by rhizomes Spring ephemeral; divide when dormant with at least one bud
Moss Phlox Phlox subulata	Spreading	Spring	Divide after flowering Branching prostrate stems can root at nodes Find center of growth to divide successfully
New England Aster Symphyotrichum novae-angliae	Clumping	Spring	Divide every 3-5 years with soil knife, saw, or edge of shovel Make sure tool is sharp to avoid damaging roots
New York Ironweed Vernonia noveboracensis	Clumping	Spring	Divide large clumps with spade or garden fork
Orange Coneflower Rudbeckia fulgida	Spreading	Spring or Early Fall	Easy to divide with spade or garden fork; divide every 3-4 years For best appearance, don’t make divisions too small
Oxeye Heliopsis helianthoides	Clumping	Not suitable for division	Spreads by self-sowing; large clumps difficult to divide
Partridge-berry Mitchella repens	Spreading	Spring	Stems root when in contact with soil Cut 6- to 12-inch piece of trailing stem Carefully uproot to avoid breaking off small roots Plant in rich, well-drained site
Purple Coneflower Echinacea purpurea	Clumping	Spring or Early Fall	Easy to divide; divide every 4-5 years for healthier plants Cut crown apart with sharp knife
Robin’s Plantain Erigeron pulchellus	Stolons	Spring	Self-seeds and spreads by stolons; divide linked plants
Rough-stemmed Goldenrod Solidago rugosa	Rhizomes	Spring	Can spread aggressively; divide with spade or garden fork Divide every 3-5 years to keep plants vigorous
Scarlet Beebalm Monarda didyma	Rhizomes	Spring or Early Fall	Spreads quickly; easy to divide Easiest to divide in spring as foliage is emerging Discard old central clump Also pertains to Wild Bergamot (M. fistulosa)
Short-toothed Mountain-mint Pycnanthemum muticum	Rhizomes	Early Spring	Spreads rapidly (4-6 inches per year) Use spade to divide and extract shallow stems
Solomon’s Seal Polygonatum biflorum	Rhizomes	Spring or Early Fall	Spreads slowly via rhizomes Leave several buds on each division
Spiderwort Tradescantia virginiana	Clumping	Early Spring or Early Fall	Divide large clump into several pieces
Swamp Milkweed Asclepias incarnata	Clumping	Not suitable for division	Difficult to divide because of taproot Best to purchase additional plants
Swamp Rose-mallow Hibiscus moscheutos	Clumping	Spring	Divide clump into pieces with sufficient sprouts
Threadleaf Coreopsis Coreopsis verticillata	Rhizomes	Spring or Early Fall	Short-lived; divide every 3-4 years Cut back plant by half
Turk’s Cap Lily Lilium superbum	Bulb	Spring	Plants spread via stoloniferous bulbs Gently twist offsets from bulb of mature plant to divide them Keep moist; plant in individual pots and transplant outdoors when 1-2 years old Make sure pointy ends face upwards
Virginia Blue Flag Iris virginica	Rhizomes	Early Fall	Divide when leaves begin to turn yellow Keep stringy roots attached to stubby rhizome sections
Virginia Bluebells Mertensia virginica	Rhizomes	Fall	Spring ephemeral; divide rhizomes while plant is dormant
Virginia Knotweed Persicaria virginiana	Rhizomes	Spring	Spreads rapidly by self-seeding & rhizomes Divide when dormant in spring
White Turtlehead Chelone glabra	Clumping	Spring	Divide every 4 years or as needed Easy to divide with spade; keep moist
White Wood Aster Eurybia divaricata	Rhizomes	Early Spring	Self-seeds and spreads vigorously by rhizomes Divide clumps or allow to spread on its own
Wild Geranium Geranium maculatum	Rhizomes	Early Spring or Fall	Rhizomes form right angles, simplifying division
Wild Ginger Asarum canadense	Rhizomes	Early Fall	Spreads slowly; divide root of mature plants
Wild Pink Silene caroliniana	Clumping	Spring	Spreads from ground-level stems Gently divide clumps in spring
Wild Stonecrop Sedum ternatum	Spreading	Spring	Stems root at nodes to form new plants Gently dig up mature plant & carefully pull apart roots to separate into sections which quickly take root
Woodland Phlox Phlox divaricata	Spreading	Spring or Early Fall	Shoots root at nodes; detach rooted stems into sections
Yarrow Achillea millefolium	Rhizome	Early Spring	Easy to divide; spreads quickly Divide every 2-3 years