Division Instructions per Species
Divide every 2-3 years in spring
Astilbe
Divide every 3-4 years in spring
Baby’s Breath (Gypsophila)
Division is difficult, carefully divide in spring or late summer/early fall
Basket-of-Gold (Aurinia)
Divide in late summer/early fall.
Bee Balm (Monarda)
Divide approx. every third year in spring
Blanket Flower (Gaillardia)
Divide in spring
Blazing Star (Liatris)
Divide in spring
Bleeding Heart (Dicentra)
Division is difficult, best done in late summer/early fall
Butterfly Weed (Asclepias)
A taproot makes division difficult. Easily propagated by seeds
Chrysanthemum
Divide every 2-3 years in spring
Columbine (Aquilegia)
Many species and varieties are short lived. Division is difficult, carefully divide in late summer
Coral Bells (Heuchera)
Divide in spring or late summer/early fall
Tickseed (Coreopsis)
Divide in spring or late summer/early fall
Cornflower (Centaurea)
Requires division every 2-3 years. Divide in spring.
Daylily (Hemerocallis)
Divide in spring or late summer/early fall
Delphinium
Usually short-lived , division is seldom necessary
False Indigo (Baptisia)
Division is difficult because of its long taproot. Plants can be started from seed
Gooseneck Loosestrife (Lysimachia clethroides)
Plants spread aggressively. Divide every 2-3 years in spring
Hardy Geranium (Geranium)
Divide in spring or late summer/early fall
Divide every other year in spring or late summer/early fall
Hosta
Plants can be left undisturbed for years. If additional plants are desired, divide clumps in spring or late summer/early fall
Iris, Bearded (Iris germanica)
Divide every 3-4 years in July or August
Iris, Siberian (Iris sibirica)
Divide after blooming in early summer
Lily of the Valley (Convallaria)
A rapidly spreading groundcover, divide in spring
Lungwort (Pulmonaria)
Divide in late summer/early fall
Obedient Plant (Physostegia)
Plants spread rapidly. Divide plants every 2-3 years in spring
Oriental Poppy (Papaver)
Divide when plants die back in mid to late summer
Ornamental Grass
The best time is spring. Also can be divided in late summer/early fall
Peony (Paeonia)
Peonies are long-lived and can be left undisturbed for years. If additional plants are desired, divide clumps in September
Perennial Salvia (Salvia)
Divide plants in spring
Phlox, Garden (Phlox paniculata)
Divide every 3-4 years in spring or late summer/early fall
Phlox, Moss (Phlox subulata)
Divide plants in spring immediately after blooming
Purple Coneflower (Echinacea)
Divide every 3-4 years in spring
Shasta Daisy (Leucanthemum)
Tends to be short-lived. Divide plants in spring
Speedwell (Veronica)
Divide in spring or late summer/early fall
Spiderwort (Tradescantia)
Divide every 2-3 years in spring
Stonecrop (Sedum)
Divide in spring
Yarrow (Achillea)
Many of the Yarrows spread rapidly. Divide every 3-4 years in spring